I find this approach really curious. All the transactions can be monitored by third parties anyway as all the pos systems are networked and subject to even lesser legal scrutiny than banks. Random adverisers can and do build comprehensive profiles. A company is us claims to have full profiles of all Americans. And yet, if there's a chance a citizen might benefit either via less hassle as in the cash case or via better gov services, everybody goes "but think of the privacy". As a result, societies get downsides of both: there is no privacy whatsoever but no value generated for the citizen.