So I just read this article: http://www.nytimes.com/2015/04/22/business/dealbook/trader-in-britain-arrested-on-charges-of-manipulation-that-led-to-2010-flash-crash.html?_r=0 ...and the last sentence was this: Mr. Sarao was charged in a federal criminal complaint in the Northern District of Illinois on Feb. 11 with one count of wire fraud, 10 counts of commodities fraud, 10 counts of commodities manipulation and one count of “spoofing,” a practice of bidding or offering with the intent to cancel the bid or offer before execution. Now I have to ask, doesn't all MMs do 'spoofing'?