How this turns into a shot at the banks I dont know.... anyway...
Full Tilt is/was a site that hosts only poker games. The gambling takes place against other players only not against Full Tilt.
Full Tilt would provide the games and take care of getting money onto the site, for that they would take a fee known as rake. The rake is where the profitability comes from.
Essentially the players funds should have been segregated from the operational funds, but they were not and were used to fund the lifestyles of the directors.
The rake would have been around a 5% per game/hand so it would have taken a long time for gamblers to "lose all there money to the house". This site was a cash cow, relatively low overheads and 24/7 earnings. The directors got greedy and thought it was ok, but then Black Friday came along and the flow of money stopped (so perhaps I see the bank link now)
Full Tilt was the 2nd largest poker operator in the world and was pure poker, no other form of gambling available, which is why it was popular, as well as having arguably the best software.
I know people that have lost a lot of money in this and all they did was place their trust in a company that gave the perception they were always working in the interest of poker. This turns out it probably isn't true now. So I hope they do some prison time for it.