> Is this really activism or just vandalism?

Analogy time. A guy sits outside my house with a camera, making pictures through a 10cm slit between the curtains. I come out of the house, take his camera and smash it. Vandalism? Don't think so. Activism? Not really. Basically, this is just self-protection. Preventing this from happening in the future (or at least making a good attempt at it).