Warren Buffett’s rule of thumb: ethics first.

From the Berkshire Hathaway's ethics code (PDF) (40KB)

When in doubt, remember Warren Buffett’s rule of thumb:
“…I want employees to ask themselves whether they are willing to have any contemplated act appear the next day on the front page of their local paper – to be read by their spouses, children and friends – with the reporting done by an informed and critical reporter"

This was used by Warren Buffet on the witness chair facing members of Congress while speaking as the newly-appointed interim chairman of Salomon Brothers during the hearing regarding their bond-trading scandal of 1990.