I accidentally carried a box of .45 ammunition through several checkpoints in D.C. one day, in the bottom of my backpack.

Gave me a start when I found it that evening on the train.

Now, I don't know how security in the capital compares to that found in airports - but you'd think it would be comparable.

Turns out all you need to do to foil security is jam a pair of socks down on top of bullets and you're set.