It’s sad that I have to write this. Objectivists have a long history of unfriending and blocking each other on Facebook for petty, stupid reasons. But there is now something serious enough to warrant shunning other people over: the alt-right is in neo-Nazi territory. There is no way around it.
There is something called the "Alt Lite," which does not go as far as the alt-right (it often stops short of making eugenicist claims about race and IQ on its own; it leaves that dirty work to the alt-right), but still treats the alt-right as just having another opinion worthy of respect. The racist and eugenicist claims are presumed, at the worst, simply to be an as-of-yet-unproven but plausible hypothesis. (Here is a mostly reliable overview some well-known people of the “Alt Lite.”) Paul Joseph Watson and Milo Yiannopoulos are in this “Alt Lite” category. Even when someone from the Alt Lite refrains from explicitly endorsing the eugenicist claims about IQ and race, the Alt Lite still normalizes and reinforces the alt-right's pathology. If I think you are promoting Paul Joseph Watson's normalization of this, I will unfriend or block you. Zero tolerance.