As part of a settlement with the Department of Justice, Google's agreed to forfeit $500m it received for selling illegal ads to for illegal prescription drugs from Canada. That number is one of the largest forfeitures of its kind, and it comes from adding up all the money Google received from illegal Canadian pharmacy ads with all the money made by the pharmacies selling to US consumers. Interestingly, the New York Times reports that Google set aside the full amount for a "potential settlement" back in May, perhaps indicating that it hoped to reach an agreement and put the case to rest as quickly as possible. In a statement, Google says that is has "banned the advertising of prescription drugs in the U.S. by Canadian pharmacies some time ago," but recognizes that "it’s obvious with hindsight that we shouldn’t have allowed these ads on Google in the first place." 

Source: Department of JusticeNew York Times, via Engadget