It's pretty obvious that they are, it's hard to track something that's anonymous. It's not like the 80s/90s when these people would congregate in groups and go to parties, etc. This is a new ball game. You also have to consider that *Channers often "shitpost" and 99% of threats aren't even legitimate.
If so what's the point in trying if you're going to expend a large amount of effort for relatively little gains. It would surely be better to accept that such forums will always exist but at least make it more difficult for people to accidentally stumble across this stuff.
