hey wxcpo your idea's are a bit extreme but as being someone who's around the internet before
Any of the "old men" will be hanging around AIM, MSN or Yahoo chat rooms. These chat rooms are 75% perverts wanting cybersex \ to meet you.
I suggest you bar your kids from chat rooms (great idea) until their older. None of the stalkers are using search's expisally if your children hide their ages in their profile.
Make sure your children hide their age so noone can do a search by age, and bar them from chat rooms (some quick pop in's and you will keep em out)
Better idea than keylogging