This is what happens when white people sacrifice social solidarity in the name of capitalistic pursuit.
Many cultures have some version of the "you're not a man until you ____", which can be toxic, but many of them still have a level of social cohesion where young men know that they will have the support of their families and local community. They are still swaddled in the warmth of a reliable social fabric. But for young, white men in our current climate, I don't know if they see themselves as having a culture.
Media consumption simply tells them that white men are defined by their success, not by their socialization - whether that success be physical (conquering enemies), romantic (acquiring a love interest/sex), mental (outsmarting others) or financial (being a CEO). The other useful source of information, parents and peers, provide conflicting information - be nice to others, but play to win. Treat women with respect, but go out and sow your wild oats. Obey the law, but "boys will be boys". Try to fit in, but be yourself. Don't say hateful things to minorities, but also don't bring one of them home to us.
There may be some psychological/neurological evidence that men, more than women, look externally when trying to find the source of their problems. It's not that they're unattractive or unfunny, it's that all the women are whores who just want to date jerks. It's not that they're unqualified for the job, it's that Blacks are being given the upperhand. So amidst their conflicted messages and their raging hormones, some of them go searching for an external "threat" rather than face the knot of confusion within.
I imagine many of these men feel alone, lost, in pain, angry, bitter, insecure. They don't realize that, from birth, society has held them to an implied contract that goes something like this: "You'll be on the right side of history and the best side of the law. You'll be rich and famous and adored. You'll be treated as the most important. The only condition is that you have to care about success more than anything else - more than family, more than friends, more than lovers, more than emotions, more than art, more than equality."
Some of them can't or don't know how to uphold that contract. And instead of recognizing the contract for what it is - a bad deal - they go looking for reasons for why they're failing to succeed. Feminists, gays, minorities, whatever. Anyone who seems to pushing back against the social grain, calling their contract into question. Where they should see allies, they see enemies.
Layered on top of this cultural issue is a biological reality: Some men have more testosterone and are more aggressive. They want more sex than they can get. They want to pick fights. Their insecurities feed these impulses.
I don't really know what to do with these young men. Talking to them via the Internet probably isn't the answer; it's too easy for them to retreat. Part of this is a cultural problem about white privilege that we need to resolve as a society; part of this is a parental problem where parents need to talk to their sons more and encourage them to be more open about their feelings; part of this is a media problem where the Internet lets assholes prey on the weak under the guise of "free speech."; part of this is a medical problem in how we relate to and treat mental health issues. The solution won't come from one place.