It just seems unlikely that it could be a coincidence that 4 of my top voted questions all get downvotes at the same time. Is there some grumpy user out there who decided they hate me and so they went and downvoted 4 of my posts? If so, that can be reversed, right?
The publicly available information certainly looks suspicious: your posts were downvoted at 03:29:28, 03:29:32, 03:29:35, and 03:29:59 this morning. They were all questions (which are free to downvote), and there's not much of a link between them - particularly the Buzz one - except that they were all posted by you. This makes it look as though someone was out to get you and went through a few randomly chosen questions of yours downvoting them.
First off, wait for the serial voting algorithm to run. It runs once every 24 hours, at roughly 3am UTC, and is designed to pick up and reverse behaviour like this.
If the votes haven't been reversed by this time tomorrow, you have a couple of options.
Flag it. Pick one of the affected posts and raise a custom moderator flag to explain the situation. We'll have a look, and if we can't do anything about it ourselves we can kick it up to a Stack Exchange employee to handle. Alternatively, you could contact SE directly yourself.
Forget it. The question is whether 'tis nobler in the mind to suffer the slings and arrows of outrageous fortune, or to take arms against a sea of troubles, and, by opposing, end them. Four
slings and arrowsdownvotes aren't much - 8 rep lost can be cancelled out with a single upvote on one of your answers - but the injustice remains, of course.
If you decide to go for option 1, do bear in mind it's possible that further investigation won't give sufficient evidence of foul play for the votes to be reversed (no algorithm is perfect, and there will always be false negatives), so you may have to plump for option 2 anyway.