Originally Posted by onlyairfare

I have had a TSO try to steal jewelry and an antique belt buckle from my carry-on at Christmas time; these were gifts I was carrying with me to avoid theft from checked baggage. The TSO was rummaging through my bag with her back to me, without my permission or my ability to observe her, at a table about 8 feet away from where I stood on my side of the X-ray belt.

Another time, the TSO who was going to pat me down stood by and observed another "pax" (I suspect she was an accomplice) attempt to steal my laptop as it came out of the X-ray. I had already identified it to the TSO as my laptop so that it could be brought over to the pat down area.

So yes, I am very cautious with my valuables at the security checkpoint. A combination lock on my bag, and a cable linking my laptop to my carry-on will reduce this type of theft.