US politicians proposed legislation which would limit the government’s ability to discreetly purchase data about citizens, setting the stage for a debate on privacy rights versus national security.

Data brokers can currently sell location data captured from mobile phones to US intelligence and law enforcement agencies.

But a group of 20 Senators called for third-party brokers to be subject to the same rules governing mobile network operators and internet service providers, which only release personal data to the government when required to do so by a search warrant, except in emergencies.

Companies developing technology to intercept data from mobile networks are not restricted from selling this data to the federal government.

“There’s no reason information scavenged by data brokers should be treated differently than the same data held by your phone company or email provider”, Senator Ron Wyden, one of the leaders of the push, stated.

The legislation is sure to spark debate about national security. Restricting the sale of third party data to the US government will not eliminate data brokers, raising the possibility they would seek new buyers outside the US.

A number of private companies have created software to collect data with the intention of selling it to the US government.

One such company inadvertently started tracking the movements of US military troops deployed overseas,  The Wall Street Journal reported.

Various media reported another company which once sold surveillance equipment to law enforcement agencies has ties with Global Resource Systems, an obscure company which appears to control more IP addresses than AT&T or Comcast.

The US Department of Defense says Global Resource Systems is helping it prevent unauthorised use of its internet addresses.