This is an only slightly hypothetical version of a situation that some of the tens of thousands of Comic-Con attendees apparently endured over the weekend, if complaints voiced on Twitter are any indication.

The thing is, any actual inconvenience that occurred turned out to be unnecessary, because on Monday, the T.S.A. said that the message put out by United was untrue. The airline, a T.S.A. spokeswoman later said, had “misrepresented” the agency’s policy on books and baggage — and potentially caused many fanboys and girls major heartache in the process.

“Clearly, comic books are not a security threat, and passengers are welcome to put them in their checked or carry-on baggage,” Lorie Dankers, a T.S.A. spokeswoman, said in a phone interview on Tuesday. The airlines, she said, “are probably trying to be helpful, but it’s not helpful to state T.S.A. policy incorrectly.”

That said, a reading of previous blog posts on the issue of packing shows how confusion might have occurred.

Still, the comic-book kerfuffle represents the latest public-relations stumble for United, which has become a lightning rod for travelers’ discontent ever since a passenger was dragged off one of its flights in April in a bloody episode that was captured on video.