Documents filed in response to a U.S. lawmaker's request show that Sprint is by far the biggest user of Carrier IQ's software, with more than 26 million handsets featuring the controversial mobile tracking tool.
AT&T, another major wireless carrier, said it has integrated the software into about 900,000 handsets, although it is collecting data only from about 575,000 of them.
[ InfoWorld's Galen Gruman says Carrier IQ and Facebook pose the least of your privacy threats. | Also see Paul Venezia's post "The Carrier IQ scandal: Enough is enough" and check out "Is a privacy backlash brewing?" by InfoWorld's Eric Knorr. | Learn how to secure your systems with Roger Grimes' Security Adviser blog and Security Central newsletter, both from InfoWorld. ]
Details about the carriers' use of Carrier IQ software were included in letters filed with U.S. Sen. Al Franken's (D-Minn.) office Thursday. Franken earlier this month had sent letters to AT&T, Sprint and several other companies demanding details about their use of Carrier IQ's software.
The letter was prompted by security researcher Trevor Eckhart's disclosure last month that Carrier IQ software could be used to conduct surreptitious and highly intrusive tracking of mobile phone users.
Franken had asked the carriers for such details as how many devices had the software installed, how long they had been using the software, what they were using it for and what data was being collected with it.
On Thursday, Franken issued a statement saying that despite the clarifications, he was still "very troubled by what's going on."
"People have a fundamental right to control their private information. After reading the companies' responses, I'm still concerned that this right is not being respected," Franken said. He added that average users had no way of knowing if the software was running on their devices, what information was being captured and where it being sent. "That's a problem, he said.
In its response, Sprint noted that it has been using Carrier IQ software since 2006 but insisted that the only information it collects and uses is related to network and device performance.
"Sprint has not used Carrier IQ diagnostics to profile customer behavior, serve targeted advertising, or for any purpose not specifically related to certifying that a device is able to operate on Sprint's network or otherwise to improve network operations and customer experiences," Vonya McCann, the company's senior vice president of government affairs, said in the letter.