What you can do; sleep with your pants on or hold your junk all night. (This is where the saying "wakie wakie, hands off snakie" came from.)
It is possible to catch this bandit, it is said that he will give you one of three possible prizes; $23(American), a walk-man, or a cassette player. which makes you wonder why you would want to catch his cheap ass anyway.
Known as: The Weiner Bandit.