...the real problem here is that people with modded consoles of any magnitude are using Xbox Live. Microsoft may have stepped over the line with disabling console features and corrupting hard drive contents, but I would ensure that the TOS/EULA has not been updated to reflect this. Microsoft has a habit of updating the TOS/EULA without acknowledgement from the User.
Skaar,
You should have known that modding the hard drive would eventually result in a console ban, as this was previously done on Microsoft's last console, the Xbox. There's a reason you had to go out of your way to mask the drivers. If you're going to mod the hard drive, do so with the correct hard drive model at least (Western Digital 120GB SATA). Microsoft's premium sucks, as half the price is just the harness.
Porksta & portnoyd,
Can we get back to the topic at hand please?
Also, Porksta, rules are indeed flexible as you've pointed out. I've been pulled over for "reckless driving" because I accelerated too quickly after stopping at a stop sign because the officer was bored, but I wasn't breaking any laws. You can break the law without actually breaking it. That's essentially the point at hand for Skaar - he broke the terms by using a non-Microsoft branded HDD, but did not do something that deserved having all of his saves destroyed.
Microsoft's view of escalation bites...stay off Xbox Live if you don't want Microsoft involved. This is why Xfire was a popular alternative to Xbox Live.