Online communities have existed for over four decades now and we still haven't solved these problems.
The beautiful thing about digital graffiti is that you can remove it instantly, and return to an unmarred environment. As long as such tools are provided to each person, those who enjoy graffiti can leave it in place too. Win-Win.
We do need a new vision, with people embracing and promoting digital maturity. Both in a reduction of trolling, and in a stronger resilience against it. Because not everything that is objectionable, is graffiti. You should not hate your neighbor because he has a different political sign on his front yard during election season. We have to stop equating everything that is objectionable, as a catastrophic, intolerable insult.