When WTC 7 fell in its own footprint (a sure sign of a demolition) all of the computer hard drives at the stock broker Salomon Smith Barney were pulverized.
This hid the identity of whoever sold short the airline stocks of the companies involved in the events of the day. Trillions of dollars were made by the culprits. ;)
"When bad men combine, the good must associate; else they will fall, one by one." Edmund Burke