the only thing i would add, is that this kid is prob. sitting there trying to learn how to hack on google.
he may download some backdoor type program (sub7) or something like that, look it up i'm not giving details.
other than that, there is prob. nothing you have to worry about... and he can "scan your ports" all day long... won't do him a bit of good unless he knows what he's doing.
only thing that's going to do is slow down his own computer/network with processs as it all fails and comes back to him... lol
besides, the odds of him actually being able to locate your computer based on a name from AIM!!! slim to none.