Is there a point at which someone should start getting paranoid about serial downvoting?

Question

Is there a point where someone can conclude that they are being serially down-voted without being an outright paranoid?

Around 11am:
~~~~~~~~~~~~   
-2; 21 mins ago; downvote; When did Eru interfere in Arda directly? ; 
-2; 23 mins ago; downvote; How many Men were there on Arda at the time 
                           of War of the Ring? 
-2; 28 mins ago; downvote; Was there an “original sin” idea 
                           in the published version of Silmarillion?

Around 2pm:
-2; 20 mins ago; downvote; What happened to Saruman after he was knifed by Grima?
-2; 21 mins ago; downvote; What is the origin of the idea of God needing
                           a “voice” in “Dogma”? 

These are 5 out of 6 questions I posted in the last 24 hours. One can be counted as statistical noise (it has 3 other DVs), but the fact that this ALSO coincided with the day when I stood up for myself against what I see an unjustified VTC makes it suspicious.

This isn't the first time I get a bouts of 2-4 question downvotes with no comments in the span of 5-15 minutes. But I think 5 in a row is more of grounds to be suspicious of people than of statistics.

Here's another couple of samples from my old emails when I noticed it happening:

May 6, 2012
-2; 4 hours ago; downvote; Were any of the Avengers involved the last ...
-2; 4 hours ago; downvote; Is there any canon proof that Elder Wand 
                           actually works as reputed in a duel?
-2; 4 hours ago; downvote; Where did the “Memories transferred through DNA” 
                           idea used in Assassin's Creed come from?

May 12
-2 2 hours ago downvote What exactly was Radagast's role among Maiar? 
-2 2 hours ago downvote What does “Seven” and “nine” mean in “Seven of Nine”?

July 12
-2   1 hour ago; downvote; Is there any evidence regarding Aragorn having 
                           a beard in Tolkien?
-2   1 hour ago; downvote; What material is the snitch in Harry Potter made out of?
-2   1 hour ago; downvote; Did any Quidditch games ever end by 
                           agreement of the Captains?

---

Just to be clear, I'm merely asking for an opinion (or rather, facts to confirm that this is a "normal" pattern). I don't have any particular desire to ask SE to investigate it. Just want to know if other people experience this frequently (e.g. 3+ downvotes in an hour, or 4+ a day) on disparate questions - and never on answers - with any regularity (couple of times a month).

I also had a more fun pattern where someone was DVing 1-2 questions a day, every day, for many days. Always within one of two 1-hour periods during the day.

---

UPDATE:

Anyone still think I'm a paranoid who only cares about rep?

Today's votes as of 1:30am EST (no intervening upvotes):
-2; 40 mins ago; downvote; Why were the Elves so great at archery?
-2; 37 mins ago; downvote; Were there any other Immortals aside from 
                           Connor and Duncan MacLeods who were relatives?
-2; 37 mins ago; downvote; Was T-X in some way responsible for Skynet's 
                           offensive actions on Judgement Day in T3?
-2; 38 mins ago; downvote; What was the first SciFi book or story 
                           co-written by 2 authors before 1957?
-2; 56 mins ago; downvote; How many R2 droid units were there according to canon?

Sep 10 2012. 
NONE of the questions are recent or have recent activity prior DV
-2; 20 mins ago; downvote; Why don't muggle-born wizards use Muggle 
                           technology to fight Death Eaters?
-2; 9 hours ago; downvote; What was the longest natural biological 
                           lifespan in Star Wars?
-2; 9 hours ago; downvote; Were there any “Starship Troopers” comics closer 
                           to the spirit of the book than the movie?

Answer 1

I really don't see the problem. A single user could cause you to loose at most 546 rep this way (right now). That seems to be what you gain about every two to three days! Note that sock-puppets do not count: You need at least 125 rep to even cast down votes.

Reputation is a number. It doesn't even cost you anything to increment other people's rep count. And above 20k it doesn't even change anything you can do (correct me if I'm wrong). There's no way you will be reduced to this unless the number of serial downvoters times the number of your questions surpasses 15000.

Since you seem to take this really personally, I'll do my best to cheer you up; Here's a picture of a cute kitty:

Answer 2

To answer your direct question, you should be concerned with voting discrepencies when you see several posts on the same day voted within seconds of each other—indicating someone is going down the list of your posts in your profile and down-voting—or when you see multiple "serial down/upvoting reversed notices" on your reputation graph (like the serial upvoting reversal you had on April 4th).

The voting activity over the last couple of days on your profile is curious, and is outside the norms of the voting activity on your profile (see below). While it doesn't have the hallmarks of serial-downvoting (several down-votes within seconds of each other), it may be worth looking into.

If you ever have a concern that something is going on, asking SE—either by emailing them or through the moderators—is the best way to get it handled, as they have far better tools than are publicly available, and have seen real serial-voting occur enough times to know when it's a real problem or when it's just the result of confirmation bias.

To that point, Izkata's queries are inaccurate, the analysis is flawed, and there's very little evidence of the conclusion reached (that you have a stalker).

To demonstrate the flaws with Izkata's queries, rather than construct a query ex nihilo, I looked at your actual reputation changes as publicly available on your user profile. Looking at January, you had 30 downvotes, 3 of which were reversed, on 15 posts and 13 days:

• 2012-01-06 - What fantasy story elicited this quote? (4 downvotes, 1 reversed after edits)
• 2012-01-07 - Does Snape have a son? (1 downvote)
• 2012-01-12 - Is there an example of a sentient plant-based life form in any of the major book/movie/TV SciFi franchises? (2 downvotes, 1 reversed after edits, closed)
• 2012-01-13 - Is there a suggested order of reading Conan books? (1 downvote)
• 2012-01-17 - Which Myers-Briggs personality is Hermione? (3 downvotes)
• 2012-01-18 - Another 2 downvotes for the Myers-Briggs question
• 2012-01-19 - Was Eric Flint's 1632 the only SF&F work/universe where fan fiction is considered canon? (2 downvotes, closed)
• 2012-01-19 - How Reliable Is Anything Mad-Eye Moody Taught in Defense Against Dark Arts? (1 downvote)
• 2012-01-19 - Why didn't some other government or corporation step in to assist with the Prawns? (1 downvote)
• 2012-01-20 - Why Are There So Many Double Initials in Comic Books? (1 downvote)
• 2012-01-20 - Another 2 downvotes for the Prawns answer
• 2012-01-20 - How old is the Spear of Destiny, and what significance does it have? (1 downvote)
• 2012-01-22 - Is there a name for this fictional technology? (2 downvotes)
• 2012-01-25 - Are E.T. and Star Wars in the same universe? (1 downvote)
• 2012-01-27 - Why was Ackbar given command of the Fleet? (1 downvote)
• 2012-01-30 - What were the things in Prisoner of Azkaban movie that foreshadowed HP6/HP7? (1 downvote, closed)
• 2012-01-31 - Is Batman ever shown explicitly using the Scientific Method? (2 downvotes)

Assuming the hypothetical stalker exists and was party to down-votes on every one of those posts, only two days (1/19 and 1/20) had multiple posts down-voted: that's not serial down-voting.

And, of the 15 posts highlighted here, 8 received multiple downvotes, indicating that multiple people thought there was a problem with the post. This leaves 7 posts on the following days:

• 2012-01-07 - 1 post
• 2012-01-13 - 1
• 2012-01-19 - 1
• 2012-01-20 - 2
• 2012-01-27 - 1
• 2012-01-30 - 1

The differences between the days when you received solitary down-votes are 6 days, 6 days, 1 day, 7 days, 3 days. But let's look at your posts on those days. These are the posts you created the day you got down-voted, indicating someone saw it as it was posted or on the front page (i.e., they didn't need to go digging for things of yours to down-vote):

• Does Snape have a son?
• How Reliable Is Anything Mad-Eye Moody Taught in Defense Against Dark Arts?
• Why Are There So Many Double Initials in Comic Books?
• What were the things in Prisoner of Azkaban movie that foreshadowed HP6/HP7?

These are the posts that were either voted on the day after you created the post, or were bumped by other activity on the question:

• Is there a suggested order of reading Conan books?
• How old is the Spear of Destiny, and what significance does it have?
• Why was Ackbar given command of the Fleet?

Given that all of your posts in January can be explained by normal voting activity: what's more likely: a "stalker" was meticuously and diabolically down-voting in such a way as to be virtually undetectable, or that the down-votes you received are the result of your posting activity (high post volume combined with multiple controversial posts)?

But maybe that's just January. According to Izkata's post, that's when this all started: maybe the stalker was just learning the ropes. Let's look at August, the last full month, and one that Izkata's post doesn't touch. You had 23 downvotes (no reversals) on 19 posts and 15 days:

• 2012-08-01 - What were Madame Maxime's horses that drew Beauxbatons carriage? (1 downvote)
• 2012-08-01 - Was the fact that Connor MacLeod won the prize in movies ever retconned explicitly in later continuity? (1 downvote)
• 2012-08-05 - How could spectators watch the Tri-Wizard events? (1 downvote)
• 2012-08-07 - Why would Worf go through puberty in ST: Insurrection? (1 downvote)
• 2012-08-09 - Why would Flitwick teach 16 year olds how to turn vinegar into wine? (1 downvote)
• 2012-08-10 - Did Tom Riddle have The Trace on him? (1 downvote)
• 2012-08-15 - Are there any statistics on how many people skip poetry in LOTR? (1 downvote)
• 2012-08-16 - Did Dobby know about Horcruxes during/before Chamber of Secrets? (1 downvote)
• 2012-08-22 - How could a beheaded Terminator search for its own head? (1 downvote)
• 2012-08-22 - Why did Grima Wormtongue choose the Palantir to throw? (1 downvote)
• 2012-08-23 - Another downvote for the beheaded Terminator question
• 2012-08-23 - Do Borg have sexual reproduction? (1 downvote)
• 2012-08-24 - How do people in A Song of Ice and Fire universe survive multi-year winters? (1 downvote)
• 2012-08-24 - What is the longest winter on record in "A Song of Ice and Fire" books (1 downvote)
• 2012-08-24 - What magical interference is permitted when playing competitive Quidditch? (1 downvote)
• 2012-08-25 - Why doesn't Harry's touch destroy other Horcruxes? (1 downvote, closed)
• 2012-08-26 - Was Snape romantically attracted to Mulciber? (2 downvotes)
• 2012-08-27 - Another 2 downvotes for the Snape and Mulciber question
• 2012-08-27 - What exactly did the Death Eaters Jr. do for Snape? (1 downvote)
• 2012-08-29 - How many R2 droid units were there according to canon? (1 downvote)
• 2012-08-29 - What is written on Darth Vader's Chest control panel? (1 downvote)

5 days had multiple posts downvoted (8/1, 8/22, 8/23, 8/24, and 8/27). Of the 19 posts, 5 received multiple downvotes. This leaves 14 on the following days:

• 2012-08-01 - 2
• 2012-08-05 - 1
• 2012-08-07 - 1
• 2012-08-09 - 1
• 2012-08-10 - 1
• 2012-08-16 - 1
• 2012-08-22 - 1
• 2012-08-23 - 1
• 2012-08-24 - 3
• 2012-08-27 - 1
• 2012-08-29 - 1

Of those posts, these are the posts you created the day you got down-voted:

• What were Madame Maxime's horses that drew Beauxbatons carriage?
• Was the fact that Connor MacLeod won the prize in movies ever retconned explicitly in later continuity?
• How could spectators watch the Tri-Wizard events?
• Why would Worf go through puberty in ST: Insurrection?
• Why would Flitwick teach 16 year olds how to turn vinegar into wine?
• Did Dobby know about Horcruxes during/before Chamber of Secrets?
• Why did Grima Wormtongue choose the Palantir to throw?
• What magical interference is permitted when playing competitive Quidditch?
• What exactly did the Death Eaters Jr. do for Snape?

These are the posts that were either voted on the day after you created the post, or were bumped by other activity on the question:

• How do people in A Song of Ice and Fire universe survive multi-year winters?
• What is the longest winter on record in "A Song of Ice and Fire" books
• What is written on Darth Vader's Chest control panel?

These are the posts from your back catalog that were down-voted "out of the blue":

• Did Tom Riddle have The Trace on him?
• Do Borg have sexual reproduction?

Comparing January to August:

• Total down-votes went down by 17% (27 to 23)
• Total posts down-voted went up by 26% (15 to 19)
• Total days with down-votes went up 15% (13 to 15)
• Total posts with solitary down-votes doubled (7 to 14)
• Total posts with solitary down-votes down-voted "out of the blue" went from 0 to 2.

At the same time:

• Total posts you created went down by 43% (136 to 77)
• Total days you posted went down by 7% (30 to 28)

That's interesting: down-votes went up but your posting activity went down. Does this mean there really is a stalker? Perhaps, but again, the evidence doesn't entail that conclusion. All but two posts can be accounted for by normal voting activity: you posted, and either the post received multiple down-votes or someone saw that post as it came up and decided then and there that the post wasn't useful.

But what about the two posts voted on out of the blue? It could've been a stalker, or it could've been something far more benign:

• The posts showed up in a related sidebar
• Someone was searching for information about the topic and found your posts
• The post was linked somewhere that a person with SciFi.SE rep frequents

And what of the increased "normal" down-voting on your posts during this time period? It could be explained by a stalker now following your posts as you make them and down-voting them, but you were only down-voted on 15 of the 28 days you posted. Was the stalker just lazy? Even more diabolical than previously thought?

Now let's take a look at something a stalker/serial-downvoter has no control over: the number of up-votes you received.

• In January, you had 958 upvotes, or ~97% of your total votes for the month.
• In August, you had 606 upvotes, or ~96% of your total votes for the month.

The percentages look pretty much even, proportional to the number of down-votes you received, but the number of upvotes you received during the two months actually dropped by 37%, which is substantially higher than the 23% drop in down-votes. The community in general was just more lukewarm to your posts, particulary to your back catalog, in August than they were in January. While a conspiracy orchestrated by the hypothetical stalker is possible, I offer a few alternative suggestions:

• The community's sensibilities are changing
• The quality of your posts have been changing
• You have a larger back catalog than you did 8 months ago, which gives more chances for people to find something to fault when viewing past posts across the site
• Random fluctuations within the margin of error

To conclude, while there's no definitive proof that a stalker doesn't exist, I do think you're being a little paranoid. There is evidence, proportionally speaking, that your posts are doing worse than they did several months ago, but there's very little evidence one person, or even a few people, are the ones causing it, and the decrease in overall performance of your posts is more due to less up-voting than more down-voting.

You have literally hundreds upon hundreds of posts, and nobody can bat a thousand. Try not to sweat the small stuff. Look at kitties instead:

Answer 3

I am of the opinion that DVK may well have a stalker of some sort. After plugging in several users to a query I came up with earlier tonight, the pattern of DVK's downvotes do indeed look very weird, especially when compared to some of the other top users.

• DVK - In January, it suddenly spikes really high and stays that way.
• Slytherincess - Unusually high number of downvotes in May and June, but not prior.
• TangoOversway - A spike in Jan, Feb (extra high), and Mar, but it drops back to normal after that.
• Pureferret - A large number of downvotes every other month (Feb, Apr, Jun).
• Major Stackings - A small spike in June.
• Sachin Shekhar - Spiked in March and has since stayed high.

Of the entire first page of users (that's 36 accounts) with the highest rep, no one else has gotten 10 or more downvotes in a single month. Examples of more normal numbers of downvotes (still from the first page) would be Jeff, Keen, Xantec, or myself.

Data up through June is currently all that's available. The queries will update when data becomes available, but this answer may not be updated when that happens.

EDIT: I should point out that the query being used in this post is attempting to single out posts so that a stalker can be more easily identified - many downvotes on one post on the same date would count as 1, not the number of downvotes, since each user can only downvote a post once. Using this query for total downvotes shows basically the same patterns.