One of the major plot points of 2007s Superbad was that Christopher Mintz-Plasse's character got a fake ID from Hawaii. The name on the ID? McLovin. Nothing else… just McLovin. So the studio thought it would be an awesome promotion to include a replica of the McLovin ID with the DVD.
While they might have intended it to be a joke and a reminder of that funny part of the movie, Hawaiian authorities didn't find it all that funny. To them, it was simply a fake ID, and they requested that Wal-Mart take it down, which they promptly did.