This from Aviation:

“Stay alert to larceny in the air
What to keep in mind to ensure your valuables are safe while flying

The Transportation Security Administration (TSA) certainly isn’t immune, either. Although all TSA agents are supposedly background-checked, more than 400 have been fired over the past five years for stealing. (It seems fair to hope some may have been jailed too, for committing crimes while serving in vitally important positions of public trust.) For the record, the TSA says the worst airports for theft are Newark, Miami, Fort Lauderdale, Los Angeles, and Seattle-Tacoma.

Steps to help prevent your items being stolen
Jewelry is the single biggest category of stolen valuables, followed by cameras and electronics. Still, carelessness and blind faith make the situation needlessly worse. So keep the following in mind:

* Don’t stash anything in your checked bags that you’d be devastated to lose, and buy one small but solid lock per bag (the TSA suggests Travel Sentry or Safe Skies brands, both of which screeners can open and relock should they decide to go into your bag). Locks occasionally do get cut off by screeners if a bag seems suspicious, but they seem to discourage casual pilfering.
* In security lines, consolidate loose items (such as phones or iPods) into one bag before putting it through the machine, and keep an eagle eye when it emerges out the other end even if you’re detained for wanding or frisking. If the security screeners bring you out of sight of your stuff, politely but firmly ask to have it brought to you immediately. Dont pass through the metal detector until your items are well inside the x-ray machine.
* In-flight, put the carry-on with all your “must-not-lose” belongings under the seat in front of you and lock it, because the passenger seated ahead of you can reach under his seat and delve into your bag. But keep wallets on your person, especially if it’s a long-haul flight. That goes for double if it’s overnight and you plan to sleep. Consider locks for any bags in overhead bins, as well; it’s not unheard of for a thief to run his or her mitts through bags while their owners are snoozing. It’s also not a bad idea to put your bag(s) in the bin across from you, the better to keep an eye on things.
* Don’t pack valuables near the tops of your carry-on bags; that makes it easier for someone casually to scoop them out, with minimal effort.”

KEEP AN EYE ON YOUR BELONGINGS AND BE AWARE WHEN USING ANY AIRPORT!