Re: I remember my PGP T-shirt well!
I wore the PGP-in-perl T-shirt out of and back into the USA on maybe a dozen flights from '91 to '93 without anybody even blinking at me funny. Later, I occasionally carried a copy of Bruce Schneier's "Applied Cryptography" book containing source examples in the text (which did not fall under the export restrictions) and the disk containing the very same source, which was bound into the cover (and very definitely did fall under those restrictions).
This kind of security theater may be worth the paper it is printed on, but not much more.
I stopped trying to get arrested on principle when I grew up and had a kid of my own to take care of. Priorities & all that. Today, she tells me I shouldn't have wimped out ... but she did take the shirt and the book into "show and tell" occasionally, as examples of governmental stupidity.
My Grand daughter (not quite 11 yet) wanted to do the same show and tell, with the same shirt and book ... and then snip off a corner of the shirt to turn into gun cotton to demonstrate how easy real munitions are to make. I nixed cutting up the shirt (too many memories), and recommended snipping a bit off of another tshirt instead. Her school nixed that option, because children aren't supposed to know such things, and IT WOULD BE DANGEROUS!!! (the school's CAPS and punctuation). Model rocketry is banned for the same reason, much to her deep dismay.
Just ten years old and she's already on "watch list" for her school district because she knows too much. What kind of useless milquetoasts are her generation going to become, anyway?