Just to let you know I've compiled your pdf on refusing a subway search into a postcard. I just recently ran a print of 100 of them and honestly I'm not sure what to do with them. I'll get them distributed to my fellow straphangers one way or another. One of the most surprising reaction to the cards was from a friend who objected to them. He asked what propaganda site I got them from that lead me to believe that warrantless searches are a bad thing. He argued that sporadic security was better then no security at all. I argued that it was a false sense of security and that it would catch no real threats while imposing on mostly innocent people. Especially since any "terrorist" would probably be smart enough to easily avoid detection.
I've attached the front and the back of the postcards, you may use them if you like. The front photo is from Runnx on flickr and I've attributed to him which is all his CC license requires. I think my next card is going to say why you might want to refuse a subway search.