The direct legal precedent was set in 2004 in the Fifth Circuit case of United States v.

FORBES: Lay Cheats Justice

The SEC has already proposed a number of changes designed to address their growing influence, including extra restrictions on broker-dealers that provide direct market access to high frequency traders, a trader tracking system for large traders, circuit breakers that would slow trading in individual stocks if they fall more than 10%, and new rules for off-exchange trading venues.

FORBES: SEC Wants Real Time Trading Data

But analysts noted that Best Buy has passed a period of easy market share growth that came after last year's collapse of archrival Circuit City, and may have misfired this holiday season by deciding not to compete more aggressively against its new direct competitors such as Wal-Mart and Amazon in favor of preserving profits.

WSJ: Best Buy's Profit, Sales Retreat