My neighbour keeps covering the camera. Whatt can I do?

I am disabled and as such I purchased a video/audio doorbell. I installed it and informed the neighbour that lives upstairs from me and he said it was fine, (We share the same entrance to the building). Over the last month every time he enters the building he slams his hand against the camera to obscure the view. This causes the alarm to sound. I have asked him not to but he has said that I am now violating his privacy and has ignored my request. Is this true? What cause of action can I take?