My experience has been different. My LM Style PS has made it through TSA screening hundreds of times and has saved the day repeatedly for small jobs.

• Beard trimmer guide failed morning before important meeting -- using the little pliers and a paperclip, fashioned a temporary repair that allowed me to trim my beard before the meeting and not look like a hobo
• I used the tiny scissors to score and cut packaging material in the parking lot outside a shipping location to get box ready to ship
• The little pliers have been effective many times in customer datacenters to hold or grab things that my fingers weren't adequate for
• Many times I've used it to open packages more effectively than a car key
• Even the screwdriver, which is definitely not its best tool has been useful in customer datacenters
• Opening beer bottles

+1.The Leatherman small tools are quite effective> My PS4 would be quite welcome in an emergency. Others are not so good. The Utili-key is just plain silly, but it does take up space in my junk drawer

Don't have a Utili-Key but I do have a LM Squirt E-4 (predecessor to the ES-4). It has proved to be very useful on more than one occasion. The wire-strippers are real but in a small package.

Mine was confiscated 9 years ago.

Allowed or slipped though security are different things...

http://abcnews.go.com/US/tsa-director-reassigned-wake-security-failures/story?id=31458476