Ok, this is wierd
 

My flatmates and I have been receving photos of our flat in the mailbox. No envelopes or accompanying notes or anything, just loose photos. There have been about half a dozen of them, arriving one at a time. I've been here the longest of the four of us, and they were taken before I moved in.

The most logical explanation we've come up with is a friend of ours, who lived here when I first moved in, playing a joke on us. Another possible explanation is dodgy debt collectors after someone who used to live here - I know of at least two former tenants who were in debt.

Yeah, that's a bit creepy.
So are these outside shots of your place or are they from the inside? I guess you really need to worry when you start receiving shots of yourself in the shower.

Start leaving pictures of a shotgun in the mailbox for him.

Set up a wireless cam, hook to a VCR and record the mailbox until the next picture shows up

Now you don't want to scare off the mailman, do you?

The shotgun thing was a joke, was serious about the cam, though

Well we haven't received any more photos since the last one. Haven't been in contact with the friend I suspect yet, but I'm fairly sure it was him.

ssander - we were talking about setting up a webcam to watch the mailbox but that would obviously be pretty much pointless now.

wario - the photos were from outside.

That's good, hope it works out for you.

Now we must think up a way to get back at your "friend".