I was going to contribute tips Re: businesses, banks and businesses spying on Citizens' expenditures until I considered this is a Web-based conversation the article mentioned are being spied on by data miners and other entities, that monitor and collect detailed private information. I will mention that data miners not only sell private information they glean to banks, businesses and advertisers, but also to the government. The government uses Citizens' private social networking information including Web-based conversations to further and launch criminal investigations and civil actions against individuals, businesses and organizations for example tax evasion cases and civil asset forfeiture proceedings that require only a preponderance of civil evidence, little more that hearsay. Government can get around (retention of Citizens private information laws) by using private data mining services that  for decades may store someone's private data mined information for future access by government, e.g. including phone information, where someone spent money by using a check or credit card. If government does away with cash, Citizens will have no privacy at all.