Bad idea.
I use my roommates Live account for multiplayer all the time. I'm sure multitudes of other people do this as well. Should the people using the accounts have cheated, the account owner would be fucked. But I'm sure nerd rage is the more prevalent and I will be countered with the reasoning of, "Good! They shouldn't be sharing anyways! That what they get for being stupid and sharing!

"
The fact that people even care enough about a gay-ass pseudo score to support giving people a scarlet "A", for cheating the gay-ass pseudo score, is pretty pathetic. They cheated the score, not the gameplay.
Get it??? They weren't aimbotting your noob ass. They weren't wall hacking into your base to kill your dudes. They tricked a stupid score counter to show a higher score than they should have had. Who the fuck honestly cares? They are going to be branded as legitimate cheaters when in reality they did nothing that affects you in any meaningful or tangible way.
Zero their score, fine, but theres no reason to be a bitch and label them something they aren't. Stop raging against the nerd machine over shit that doesn't even involve playing the game.
(I wish I could make this smiley bigger to express my extreme disappoint in you non-empathetic losers with zero grasp of reality)
I use my roommates Live account for multiplayer all the time. I'm sure multitudes of other people do this as well. Should the people using the accounts have cheated, the account owner would be fucked. But I'm sure nerd rage is the more prevalent and I will be countered with the reasoning of, "Good! They shouldn't be sharing anyways! That what they get for being stupid and sharing!
The fact that people even care enough about a gay-ass pseudo score to support giving people a scarlet "A", for cheating the gay-ass pseudo score, is pretty pathetic. They cheated the score, not the gameplay.
Get it??? They weren't aimbotting your noob ass. They weren't wall hacking into your base to kill your dudes. They tricked a stupid score counter to show a higher score than they should have had. Who the fuck honestly cares? They are going to be branded as legitimate cheaters when in reality they did nothing that affects you in any meaningful or tangible way.
Zero their score, fine, but theres no reason to be a bitch and label them something they aren't. Stop raging against the nerd machine over shit that doesn't even involve playing the game.
How does LIVE know a player has been cheating on their gamerscore versus another player?
We look for abnormal achievement and gamerscore activity using criteria that identifies users who have used external means to earn achievements without really playing the game. Users who play games legitimately to earn an achievements are unaffected by this.