I've always remembered this quote from a book that I read as a kid. It was something along the lines of "What's scary is not necessarily what goes bump in the night, but that which whispers at midday. " And I've always held that. The day can just be as scary as night.
As for the European far left, it has very little to do with Marxism-Leninism these days. It has more to do with anti-Semitism, racism, anti-migration. They claim to be left-wing but they're espousing positions which would actually be classically brown.