[Mika]

Where I live, the police can do something about that. I still don't understand why you don't call them regardless? If they can't do anything, they'll say so. If they can, then something will be done.

It's really stupid to wait for it to escalate before calling too because then you don't have a record of filed reports. If there's not enough to go on yet, they still file a report which could really make a difference in your case. It proves there was a history to it if it gets out of hand, so you should probably call anyway.