1. US dollars in cash has a serial number on it, the government can trace it easily because they could ask banks for the certain serial numbers to report it as

1. US dollars in cash has a serial number on it, the government can trace it easily because they could ask banks for the certain serial numbers to report it as a blacklist(easy, they are automatic OCR machines for it). 2.Cash is becoming less and less important, the gov prefer the credit card electronic version when people tell everything they buy(when,where and what) to the gov. Electronic currency is the future because of convenience so they do not want people to break free from the Gob(BTW as they were in the past). 3. There is no limit in the number of Bitcoins you could use before being controlled,as there are with cash. 4. There is no limit in the number of US dollars the gov can print to dilute them as they are with Bitcoins. 5. US dollars are losing value, Bitcoins are getting more appreciated.