Communication security

The NSA warned staff that smartphone apps can track them. Here are their recommendations to avoid tracking.

The National Security Administration warned staff that the amount of data their smartphones track could pose a national security risk in new guidance issued Tuesday. 

The guidance highlights a practice that's common across Silicon Valley products but rarely understood by consumers: smartphones are constantly gathering information on users' location, through a combination of apps, the smartphone's own hardware, and the telecommunications networks that they use.

Apps typically share that data with third-party brokers, who in turn sell it to clients including private companies and government agencies. The data is anonymized, meaning it's not directly tied to a person's identity — but researchers have consistently found that anonymized location data can easily be traced back to specific people.