It appears that some folks think that they have found a way to get an advantage while playing some online games.
If other users find out your IP, they initiate a denial of service spoof attack on you which can get you booted from the online server, or slow your connection down enough that you cannot adequately defend yourself in the games.
I have recorded two of the attack IP addresses and will begin a list for my own use.
The Whois internet sites are identifying each and I have saved them for future investigation.
(One came from Cambridge, MA and the other from Redmond, WA.)
I don't know if any of the smart folks at Microsoft are reading these, but you might want to look into this.