This recent question received an inexplicable downvote from some user who apparently downvoted every other question that was asked at around the same time. Can moderators find out exactly who this person is and bring him/her to task? I know that there are similar questions on meta to the one that I am asking here, but this is not an instance in which a certain individual is being targeted, but rather the community at large.
Nope. The tools moderators have are not precise enough to determine who voted on which posts (let alone at which times). Or even how many votes were given within short time-frames. We're only given tools to help identify targeted voting (targeted, that is, towards individual users). Even here precise details are not given to us, and we're given more aggregate information.
Community Managers, on the other hand, should be able to determine this. There is a contact us link at the bottom of every page. I don't think I heard of a mass-but-not-targeted-voting complaint being raised before, and IMHO it is questionable what, if anything, they would do about it.1
1 In fact there was an event in, IIRC, Dec 2013 where a user began to suddenly downvote arbitrary posts of generally high-reputation users. The moderators knew who it was after certain thresholds were passed, and the SE team was undeniably aware of the situation as well. In the end the account was deleted, but having been a high volume voter — before this unfortunate turn of events — all these downvotes were retained.