> If there were places IRL where the average person is subjected to a constant barrage of callousness it wouldn't continue to exist, would it?

Is this not why the real issue is related to social media itself, rather than generalised "trolling"? This isn't as much of an issue in niche forums or niche-dedicated social sites.

We are free to make our accounts private, block/sign out/delete/not partake in social media, yet many feel like they are __unable__ to make use of these features. IRL, you can't always easily escape bullying. Online, you can choose not to engage; yet people continue to place themselves in the line of fire. I think this speaks to a much deeper issue (as you point out) and I'm not sure jailing trolls is the answer.