They tried http://en.wikipedia.org/wiki/Pump_and_dump which is illegal.

dagw · on Oct 15, 2010

This was not a pump and dump scheme. Pump and dump involves manipulating the price via spreading false information, which is not at all what they did. They manipulated the price by actually executing trades and predicting how (certain parts of) the market would react to those trades.

yummyfajitas · on Oct 15, 2010

True, it's not pump&dump. It's "painting the tape". Still illegal.

http://www.investopedia.com/terms/p/paintingthetape.asp