They used to play this at Newcastle Uni for O-week: you were given a water pistol, a name and a photo. Once you 'shot' that person, you took the photo and name of the person that they were hunting. At the end of the week (or two?) the person with the most photos won.
Things were creepy one year as one of the guys would go to the electoral office and find their address, then just sit outside their house until they walked out (or in, as the case may be). Apparently he got someone at 3 in the morning, on their way home from somewhere.
Anyway 🙂