I've heard other people say similar claims (about Twitter hosting equal/greater amounts of hate speech, threats, etc.). Totally plausible and I wouldn't be surprised if it were definitively true, but have there been any data driven studies to back it up?

Don't know if sentiment analysis ML algorithms are powerful enough to do something like this, but there has to be some scientific consensus on the relative hateful content that each site allows right? Or at least some pretty graphs.