When you go through customs and they ask about $10,000 limit - They already know how much you have. The strips are RF.
http://www.businessinsider.com/new-paper-puts-chips-in-cash-2013-5
http://www.kurzweilai.net/are-you-ready-for-rfid-chips-built-into-your-money-and-documents
http://www.businessinsider.com/new-paper-puts-chips-in-cash-2013-5
http://www.kurzweilai.net/are-you-ready-for-rfid-chips-built-into-your-money-and-documents