A few days back an exploit was discovered allowing anyone to download the Call of Duty 4 beta as long as they could get someone who was already in the beta to recover their Gamertag on a different console. Well, that exploit has since been fixed and is ineffective for getting beta access, but those who used it aren't walking away free and clear.
Xbox-Scene is reporting that their internal Microsoft source has confirmed with them that over 23,000 consoles have downloaded the the CoD 4 beta via the exploit and that Microsoft is punishing those users. Supposedly, anyone who used this exploit will be banned from Xbox Live for a 24 hour period due to violating the terms of service agreement. In effect, the Live ban is more of a slap on the metaphorical wrist than a full scale Xbox Live ban.
We have yet to hear from or confirm these 24 hour Xbox Live lockouts, because we don't know of anyone who got in the CoD 4 beta via the Gamertag recovery exploit. But if these mini-bans turn out to be true, then we're sure the complaints will roll in soon enough.