If you are using a service like Twitter or Facebook then you’re in an inherently unsafe, unpoliced environment.
As I said here.
These services need to reform how they handle this stuff (and Twitter has made some strides) otherwise when you use Twitter and Facebook you are making the virtual equivalent of travelling to Iraq, Afghanistan, Pakistan, or the Ukraine.
You should have no expectation of safety on Twitter or Facebook, because there is none. Free speech, to these guys, means unlimited hate speech and bile. They are unmoderated spaces, libertarian paradises on earth.
The answer to “don’t feed the trolls”, is to stay in strongly moderated spaces where this kind of bullshit is not tolerated under the banner of free speech.