After TwoX went default the mods were flooded with user reports of abusive comments and threatening PMs. The mods investigated the reports and found that all but "two to four" were false flags made by sockpuppets.

TwoX mod from the thread "It's been two weeks since TwoX became a default":

There are a lot of people that seem quite invested in trying to get the mods to remove this subreddit from the defaults, and unfortunately that means that they're willing to try to cheat, lie, and do various other unsavory things to influence this decision...

Some people have even been performing what's often referred to as a "false flag", where even though they're actually normally a contributing member of the subreddit, they've been creating alt accounts to make or upvote harassing comments/messages in order to make that issue seem more prevalent than it actually is. And on the topic of harassing PMs, one of the most frustrating aspects of the situation from our perspective is that there's been a significant amount of lying on this end. We've received quite a few reports about users who have claimed to have received a large amount of harassment, but when we investigate we find that they've often never received any PMs at all, or only one message when they claim to have received many. Some people have even gone so far as creating alts to PM themselves with, so that they can take screenshots for "proof". I'm certainly not trying to say that there hasn't been any harassment, because some definitely has actually occurred (and please report it to us by sending a modmail to /r/reddit.com if it happens to you[1] ). But between the various outside groups trying quite hard to push 2XC out, the false flags, and the lying, please take all claims about it with a large grain of salt...

Out of all of the reports that other people have sent our way (generally it is other users reporting things to us on someone else's behalf), I'd say that maybe only two to four have been legit...