I've been the target of serial down voting before, so I'm familiar with the auto-script that will undo it if triggered, but the exact trigger is not publicly known. I'm also familiar with the secrecy of votes in general and that only certain developers can view them under certain circumstances. This seems like a certain circumstance that warrants a look to verify whether there's been a misuse of the SE system.
I don't participate much here. As such, my reputation changes are few and far between. Yesterday I received two downvotes only a minute apart. Today I received another. All three were on different questions. My rep changes before that are 2 upvotes 5 days before and 1 upvote over a month ago, all on questions I asked at that time. The last time I received a downvote (1 of 2 total) was nearly 2 years ago.
These recent downvotes are highly unusual.