Actually ironic since it recently happened to me.
3 or 4 weeks ago I come home and Realize my 360, memory card, one of my controllers, and just to rub salt in the wound my copy of Mass Effect 1 that I was trying to get through, fortunitly they didnt see ME2.
Belive it was a former friend, went back straight for it, made sure theyt got all the wires and plugs, and took a dagger of my friends(why I suspect them). Have no proof but its one of those strong Cop hunchs you feel in your gut.
But the jokes on them: The harddrive is fragged (was going to get a new one) cant play the Xbox with the hard drive attached, barly recognizes discs anymore, and they forgot the battery charger(wasnt plugged in) so their stuck with a controller they cant play

. Was going to update my hardrive now have to spend my income tax check on a brand new system. However Im going to get the 400$ Final Fantasy 13 360 bundle, comes with game, two controllers, and a 250GB harddrive, talk about an update!(Already reserved for March 9th)
All and I come out ok but now I have to replay all my games, lot of Bioware and bethesda among other A-list titles some of whom i invested dozens upon dozens into. I'll never get those hours back.