6. Does your son use Quake?
Quake is an online virtual reality used by hackers. It is a popular meeting place and training ground, where they discuss hacking and train in the use of various firearms. Many hackers develop anti-social tendencies due to the use of this virtual world, and it may cause erratic behaviour at home and at school.
If your son is using Quake, you should make hime understand that this is not acceptable to you. You should ensure all the firearms in your house are carefully locked away, and have trigger locks installed. You should also bring your concerns to the attention of his school.