The FBI's Security Guide for Protecting Children Online

The FBI has put together an excellent resource for protecting your children on-line.  This guide is written for parents and it contains an excellent analysis of how to tell if your kid is doing something on-line that they should not be doing and what to do if you find out.  In summary, they want parents to know:
The signs your child may be at risk to on-line threats:

• Your child spends large amounts of time on-line, especially at night.
• You find pornography on your child’s computer.
• Your child receives phone calls from men you don’t know or is making calls, sometimes long distance, to numbers you don’t recognize
• Your child receives mail, gifts, or packages from someone you don’t know.
• Your child turns the computer monitor off or quickly changes the screen on the monitor when you come into the room.
• Your child becomes withdrawn from the family.
• Your child is using an on-line account belonging to someone else.

Click Here for the guide.