in some rare cases - they can brick your console to an extent - normally, it's just a live ban, so your console still owrks and can be updated offline, but it cripples your profile, so moving from a banned console to another console bricks your profile, but this can be un-done
You'll be grilled for about 8 hours and left without food or water until you crack.
If you're lucky, they'll only remove two toes during questioning.
seriously, the only thing that will happen is your console won't be able to connect to Xbox Live and any profile you create/update (including gamesaves) on this console won't work on another. That's resolvable should you need to get it working.