Well I'm in university and live with 9 other people (10 if you count a friend from my lectures who basically lives with us any way) so yeah, there is always plenty of trickery, the most golden moment of which was when a friend and I wrote a letter on my computer and made it look like it was from the university; logo, return address and fully bilingual (I go to a Welsh uni) - It looked very authentic.
We sent it to two of our flat mates and they both bought it. The funniest thing I've ever seen. Any way, this is how the letter read....
Official Notification
Dear Mr Clark
It has been brought to my attention, by a member of the internet communications department that a person or persons from your flat study room (Room D42) has been accessing excessive amounts of pornographic material using your rooms university connection. While the viewing of material of an explicit nature is not against the terms stated within the accommodation license agreement, such frequent viewing is unacceptable.
While no formal action will be taken against you at this time, please understand that if you continue to access pornographic sites with the frequency that you have been doing so, I will be in further contact with you to issue an informal warning under the accommodation license agreement (4.7) that you signed.