PokerStars Bans Sorel Mizzi
Recently, PokerStars banned the Canadian Sorel 'Imper1um' Mizzi for three months from every game. The reason: a friend of Mizzi temporarily played the $300 PLO Event of the WCOOP for the young online pro.
At first, PokerStars apparently even imposed a six-month ban, but reduced it to three months after some intense e-mail communication with Mizzi. By his own account, Mizzi asked a friend to continue playing the tournament for him, as he had to catch a flight from Barcelona to London.

Many pros still consider multi-accounting and account sharing as a peccadillo. However, the poker sites move in against such acts more and more often with severe penalties.
Only a few weeks ago, PokerStars banned Josh Field after he had created several new accounts, and then also sanctioned several accounts of his friends who had sent him money.
PokerStrategy News: PokerStars suspends Josh Field yet again