The banking establishment is suffering a downgrade of status as they seek public bailout funds. Use of the term "banksters" (adapted from gangsters) has become widespread. What is fair?
Not much. In this case, margin (credit) and derivatives purchasing is a type of gambling. The problem is that gamblers take account of the fact that if they lose they'll not need to pay - Joe Public will bail them out; they remain players. If rather they win, they enjoy huge benefits.
A low downside means they've been likely to gamble even more; given the chance, they'll again gamble wildly.
Bankers who've engaged in unacceptable risk management should be fired. Yet these high-rollers still have their jobs. They now keep a low profile, refusing to lend even in low risk cases, creating a credit crunch. Each bank has many scamblers...