The current scandals over how large companies have been cooking the books reminds me of a basic accounting course I took years ago.
The professor was explaining an accounting method called "First In Last Out," which is useful for industries that accumulate large inventories of stuff.
It explains why the oil industry, for example, reported huge profits during the 1970's when the oil shortage occurred. They stopped buying oil, so they had to use oil that, on paper, had been purchased in the 1930's at 20 a barrel. They of course sold it at current market prices, which accounted for their huge profits.
One of the students put up his hand and said, "Excuse me, sir, but that doesn't sound very ethical to me." To which the professor replied, "You're in the wrong class, son, this is Accounting 101. Ethics 101 is two doors down the hall, on the left."