If you’re going for some kind of moral victory, don’t kill the plant. Go to the council or whatever authority is relevant in your area and force the owners to take care of their shit through legal means. There’s probably some kind of accessibility law you can press to clear the curb of tree branches.

Cutting up random people’s plants is an excellent way to run head first into tree law. Replacing these plants isn’t cheap. The guy did extensive damage to a bunch of hedges with no warning or communication beforehand, and got angry when approached.

If you’re going to risk breaking tree laws, at least don’t put your name and picture in the news.