Flying and TSA Security Checks

Does anyone have any history with air travel and the TSA? It used to be that a simple plastic device combined with a lock was enough to sidestep trouble, but lately scatter-back radiation machines are everywhere at airports doing full-body scans. These scanners don’t mind metal; anything beneath your clothes gets picked up on screen.

Has this caused any problems or pull-aside checks for you? I know every airport handles it slightly differently depending on how the staff reacts.

I haven't had issues with a plastic lock. I'm not sure what they actually see, but no one has complained. No giggling either. It is curious whether they can spot the cage on my penis.