GoKawiilValve staged Left 4 Dead 2 trailer 'leak' to dodge ESRB marketing rules
Former Valve writer Chet Faliszek revealed that a 2009 trailer for Left 4 Dead 2, widely reported at the time as leaked footage, was actually deliberately released by Valve itself. The company took this route after the ESRB refused to approve the trailer for official release, citing its graphic violence, gore, and crude language.