blockchain.info marks the sending address as BTC Guild. AMs account (67117) on BTCGuild is still sitting around the same hashrate it's been at for the last month or so (270,868.32 GH/s). Just a little confused on what might be happening here.
Also, there is no user on BTCGuild even approaching the estimated 13PH:
https://www.btcguild.com/index.php?page=rankings