Optiver is getting an inquiry by the CFTC for manipulation of oil future prices in Chicago. http://www.nytimes.com/2009/09/04/business/global/04optiver.html
I interviewed with the guy who got in trouble for banging the close......biggest prick i have ever met, i hope he goes to jail
in my opinion there has to be more than one prop trading house or bank etc who tries to "gun for the stops" and use "god forbid" spoofs / flashing of size and whatever else they deem nec.. to make a buck in whatever market "sandbox" they play in hopefully in yrs to come the playing field will be more level and there will be less slippage and "shakeouts" for all concerned
The problem in the US market is the exchanges & dumb SEC. The exchanges encourage all this shit so extra fees are paid to them. The dumb SEC listens to the scammers and makes a decision "fair to all players". 'Seems like things are 10x worse than when specialists were in charge.