Bans to expect

Things that one can easily kill people with

Knives
Guns
Pointy sticks
WMDs

Things not very suitable for killing people with

Videos
CDs/DVDs
Books (unless very heavy)

Activities that will make you a more effective killer
Sports!
Weapons Training
Consuming Crack, Red Bull, PCP
Studying medicine

Activities that in the long term will interfere with your ability to effectively massacre people
Playing computer games
Spending time on 4chan
Consuming booze, dope, sweets
Wanking (A sore hand cannot hold a gun)

A really stupid place to keep guns and ammo
Lying around in the bedroom

You get my point?