When people argue for robust "report spam" and "report abuse" tools on social media, I always have a reservation: those tools are inevitably abused by unprincipled people who want to silence speech they don't like.
Twitter is no different. The report function on Twitter is routinely abused in an effort to attack political opponents.1
In a mildly creative twist, some abusers flood opponents with huge numbers of spam followers. Then they report the opponent to Twitter. See, buying followers is a breach of terms of service, and flooding someone with spam followers makes it appear they have bought followers. If you want to protect yourself from this, the best way is to make your account private — which achieves the abuser's goal by reducing your audience.
Today Popehat's twitter account got hit with about 20,000 spam followers in the course of a couple of hours. That attack followed, by about an hour, my posting the Popehat Signal seeking help for bloggers sued by Brett Kimberlin. Some of the bloggers sued by Brett Kimberlin have also been attacked by surges of spam followers.
But I'm sure all that is just a coincidence.
Twitter makes this extremely difficult to deal with, because it is laborious to block spam followers one by one, and because Twitter forces you to contact support via form, and yet there is no suitable form for this situation.