I’d try not to let it aggravate you. It is literally just one troll who is making a bunch of accounts & setting them up to randomly flag anything & everything. They took some flags themself, in a much more legit way, and have sworn revenge on the world!
As these accounts have 15SP and very low voting power due to the number of flags thrown, they’re doing no damage. There are some users setting up counter bots who will in turn upvote anything flagged by this auto flag ring.
The upcoming hard fork should help alleviate abuse like this of the initial Steemit delegation, but we still need education to get people used to the concept itself of being flagged. If a no rep, no SP user with no posting or voting history except throwing flags attacks someone, obviously it’s not to be taken personally or worried about.