Considering all the cheats are entered via mobile phone, it could be a lot harder to do that. Assuming all the numbers are XXX-555-XXXX, that allows for 10 million possible combinations Not to mention the button presses to enter the cheats are a lot more complicated.
XBL Gamertag: JWRebholz
PSN ID: jwrebholz
...No, I'm not very creative when it comes to this sort of thing.