I understand dvs are part and parcel of the site - and a lot of you know my thoughts about their use. Today (so far!) I've had four, and feel there may be a serial dver on the loose. (It won't be the first time for me). How can mods get involved - can they alone be allowed to check on who it may be. As in, if all of them emanated from the same source, could they know?
(I'm interested to hear what my more experienced colleagues say about this, but here's my response.)
We can't see where these votes are from, nor can we reverse any votes; the only things we can see are the rep changes that you see and a little bit of extra data on voting statistics. You had four in a row in a very short time span, which certainly looks suspicious. (Like you, I'd bet money on those coming from the same user.) It wasn't enough for the system to catch any kind of downvoting spree, so there's not much we can do currently. If it continues happening, let us know, and we may need to get a community manager involved if it gets serious enough.
You may also be interested in Random Downvoting over on Meta.SE.