A smartphone security researcher is shining light on a hidden program that tracks activity on Android, BlackBerry and Nokia handsets.
Trevor Eckhart exposed the workings of Control IQ in a video available online Wednesday as the California company behind the software defended it as a tool for mobile network operators.
"Our software is designed to help mobile network providers diagnose critical issues that lead to problems such as dropped calls and battery drain," Carrier IQ said in a press statement.
The company denied the software logged keystrokes or tracked smartphone users.
However, Eckhart's video showed Control IQ software buried deep in an Android-powered smartphone recording buttons pressed, Internet search queries, text messages and locations.
Eckhart typed a text message of "Hello world!" only to have it instantly appear in a Control IQ application log in an Android phone.
The software was tricky to find on the device and couldn't be turned off, according to his demonstration.
Control IQ had tried to silence Echkart with a cease-and-desist letter threatening legal action but backed off after lawyers at the Electronic Frontier Foundation (EFF) went to his defense.
"Mr. Eckhart's legitimate and truthful research is sheltered by both the fair use doctrine and the First Amendment," EFF senior staff attorney Marcia Hofmann wrote in a response to the Control IQ letter.
Eckhart wanted details regarding why the Control IQ software was vacuuming information about smartphone use and who they shared it with.
Explore further: Singapore moves to regulate taxi booking apps