Former Valve writer Chet Faliszek has revealed that the widely publicised 2009 "leak" of a Left 4 Dead 2 trailer was actually orchestrated by Valve itself, in order to sidestep the Entertainment Software Rating Board's (ESRB) marketing restrictions. At the time, the ESRB enforced strict guidelines on trailer content, prohibiting graphic violence, weapons use, gore and crude language, and Valve believed the footage would not have been approved through official channels, so it seeded the clip online to spread virally instead.

Valve had already clashed with the ESRB earlier in 2009 over a promotional image showing a hand with three severed fingers, which had to be reshot with the digits merely curled rather than missing. The ESRB had also previously forced the removal of trailers for other games, such as Dark Sector and The Darkness, even after they had circulated online behind age gates, citing rules against excessively violent or offensive content. Faliszek noted Valve was simultaneously fighting censorship battles over the game in Australia and Germany, and said he now feels safe admitting the ruse given it happened roughly two decades ago; the same footage was later used as the game's actual intro cinematic once it received an "M for Mature" rating.