Black Lives Matter is a hate group and a domestic terrorist organization. Same goes for Antifa and the various alt-right groups.
By extension, that leads to another unpopular opinion of mine: there is not only an alt right, but an alt left as well.
Basically no one describes themselves as "Alt-left", so I'd say the alt-right is much more of a real thing for that reason alone.
They may not call themselves alt left, but that doesn't mean it doesn't exist. Groups like Occupy Wall Street, BLM, Antifa, etc. are basically the left-wing equivalent of the alt right.
Ummm no. The alt-right basically believes that all blacks, Jews, and other undesirables should be rounded together and killed. Antifa believes that those opinions should never go unconfronted and BLM believes that Blacks shouldn't be forced to the bottom of the social totem pole. If we'd taken the non-violent approach to fascism in the 1940s, WWII would have had a very different ending.