I'd make sure you tell the police about this, and give them dates and times, take photographs of it showing how close it's going to your house, especially if as you say it's 'opposite your bedroom window', and also tell them about who you think it is. It's causing a nuisance, which is one count on which you might if you wanted bring a civil action, but if this individual is photographing the inside of your house, which seems possible, there are any number of unpleasant motivations which would be of interest to the police. At the very least, they should undertake to go round and have a word.
I'd be wary of trying to damage it. That would be criminal damage and if it's got a camera it wouldn't be hard to prove who dunnit. Depending on how well you get on with the person you suspect, it might be worth having a friendly word yourself and pointing out that you don't appreciate having your privacy destroyed. This might be enough: the person may be no more than a bit of a geek who doesn't quite understand other people too well. Or it might be a young person who ditto. If that doesn't work, then make sure the police are aware and keep a record.
Which part of stafford is this happening in?
