Yeah, that looks like oak processionaries. They can cause skin irritation and apparently asthma, too..

No, we do not kill anything unless they are definitely invasive, which these guys aren’t. They are only a problem if you happen to sit on one, (and you happen to be naked, I suppose) generally they are not a nuisance at all. They stay in their tree, dispersing to eat during the day, and getting back together in clumps like this at night.

In Germany it's the same with some of these ("Eichenprozessionsspinner" can cause dangerous very serious inhalatory problems).

Not here, they are where they are supposed to be, on an acacia tree.