How about this poor guy?
Man arrested, cuffed after using $2 bills
http://www.freerepublic.com/focus/f-news/1379476/posts
Wow! That really torques me. Of course the ink on bills can smear - if you rub fresh bills on white paper often they'll leave a smudge of green behind.
Sounds like a shoddily run business. The screwed him twice. Incorrectly charges the man and then doesn't train it's employees in US currency and it's characteristics. The pen they use isn't to see if it smears, it's to see if it changes color (i.e. isn't printed on the real cotton paper.) If they had an hint of decency, they would have issued an apology to the man.