QUOTE(The Cuddly Ninja @ Jun 22 2011, 10:37 PM)
Then surely if someone goes online to do modding for a few hours, before they get banned, they will have to update? Or can they disable it somehow. And also there is no possability that my xbox is jtaggable as it has been online?
I assume you're talking about modded lobbies or something, which I've never done.
You can update a JTAG's kernel, just not in the normal way. That means you can get online because it will report the correct kernel to Live, but then you'll be banned pretty much instantly. My own JTAG is updated to 13146, and has the update for the new game discs. I didn't run a system update to do it, I had to patch my NAND and flash it to get the update.
As for your own box, check the dashboard number. Chances are you won't be able to JTAG it if it's been online within the past 2 years. Only way to be sure is to check the dash number and then dump the NAND.