In all honesty, I have no clue. Guessing that somehow you are on a lender's list due to being behind on your mortgage--perhaps they consider you pre-foreclosure and people are trying to line up to buy your home at a distressed price? Again, just a guess. As far as the privacy issue is concerned, I would also guess they can photograph from the public street but not sure that they can photograph you as individual w/o your consent (Again, not my practice area; this is just a gut feel). Either way, if they threaten you, perhaps contact the police... Sorry to not be more helpful.