the 2 dollar bill guy is only part of the story...
He walked into a store to prove a point and used sequential (and many of them) 2 dollar bills which would set off a warning for most people. Stores have a right to refuse ANY currency they wish for any reason. Same reason some places can refuse a full order of unrolled change.. because they don't want to count it... doesn't matter why..
read this if you're curious
http://legallad.quickanddirtytips.com/legal-tender.aspx
So. That being said.. the man continued to argue and cause a scene which caused the police to be contacted... Then he continued the scene with the police.. which caused him to be arrested.. then he continued the scene.. which caused for the news media to get involved...