Chicago Tribune: Airlines pledge to fix glitches for PreCheck passengers Still, it's becoming clear that the program suffers from major bugs. Citing security protocols, TSA officials declined to provide data requested by the Tribune on how many PreCheck-eligible passengers are being denied access to the special security lanes. Meanwhile, they said, the TSA screening officers assigned to them often stand idle, while backups occur at the regular lanes....A security official with a major airline said the TSA changed the PreCheck eligibility criteria in mid-July, based on issues that involve certain travel patterns. "It affects all carriers in the PreCheck program, and that is causing some of the kickbacks passengers complain about," an airline official said. The TSA has promised the airlines that the issue will be resolved in September, said the official, who asked to remain anonymous....Aviation security sources said terrorists could try to game the system by achieving frequent fliers status and circumventing regular airport security.Terrorists wouldn't be that creative, would they? Hmmm ... Does that mean that an aspiring terrorist would have show the same "certain travel patterns" as a mileage or segment runner?