What you are saying is they are awesome at stopping invisible pink elephants, they just cannot show them to us because they are invisible.
Every place in the USA has city, county, state and federal police with incredible laws that let they do almost anything they want, yet there is still crime. Somehow the TSA magically has no crime to show for their presence.
They stop about 20 to 30 handguns each week. I don't know how many guns they don't stop.
Some of those are loaded. TSA doesn't care about handguns in checked in baggage, they even advise people how to travel with guns. They do care about handguns in carry on bags.
I mean since they are seizing thousands of nailclippers each month across the country and then auctioning them, they must be seizing the handguns too.
This articles says they don't sell the handguns (perhaps that varies by state?): http://www.msnbc.msn.com/id/46934445/ns/local_news-lancaster...
(http://www.tsa.gov/travelers/airtravel/assistant/editorial_1...)
looking at the "Week in Review" posts you see the number of guns, handily broken down into loaded and unloaded. The charts list how many guns had a round chambered.
(http://blog.tsa.gov/search/label/guns)
I have no idea how many people the TSA screen each week; nor how many guns make it through screening; nor whether any of the people trying to take guns on board a plane have any intent to harm people.
http://www.schneier.com/blog/archives/2006/09/expensive_came...
It's so common they don't even bother doing a press release anymore. Sometimes they write about interesting finds on their blog:
"Over 1,200 firearms were discovered at TSA checkpoints across the nation in 2011. Many guns are found loaded with rounds in the chamber. Most passengers simply state they forgot they had a gun in their bag."
"Small chunks of C4 explosives were found in passenger’s checked luggage in Yuma (YUM). Believe it or not, he was brining it home to show his family."
http://blog.tsa.gov/2012/01/tsa-top-10-good-catches-of-2011....
Not convinced this really makes travel safer, but they do find a lot of stuff...