As mcdevitt1985 has reported (linked above) along with some users from our own XBox 360 Forum HERE, it appears Microsoft is on another XBox Live ban rampage.
According to reports, today they have issued a new wave of bans against XBox 360 consoles with modified DVD firmware. That being said, it's recommended to stay off XBL for the time being if you have a modified system until further details are available.
To quote: Dunno if its a massive wave or not, but my console was literally just banned from live within the hour.
If anyone else gets banned let me know please. iXtreme 1.4 and all games were burned right and stealthed. More PlayStation 3 News...