That Finnish cyclist pulled a stupid move, got honked, and then was an asshole. If he continues pulling stupid moves like that, sooner or later he will be accidentally run over by a driver who doesn't notice him.
The American car driver in the second video was out of his mind.
We have "critical mass" bike rides here from time to time. They're usually relatively well-behaved, taking up the traffic lanes on one road going in one direction. It's much like watching a circus go by. Certainly messes up traffic, so thankfully they're only on weekends. Some drivers have a problem with it, and force their way across the street. As far as I know, the organizers usually have a couple of cars to follow behind the cyclists, so that drivers can't try to drive through the group of riders. Though I guess that wouldn't stop a crazy person from driving on the wrong side of the road, crossing the centre divider, and then ramming through the bikes...