I think the professor was arrested for being uncooperative, not for having a bagel. Just to play it safe, you can now screen for suspicious bagels in the TSA Opt-Out Day game.
None of the news stories reporting on the bagel incident have included an actual photo of the suspicious bagel, so I have created an "artist's" interpretation of the device. You can see it in the screenshot of the game to the left. If that isn't a suspicious looking bagel, I don't know what is.
Let me know in the comments if you know more about bagels and airplane safety.