Carrier IQ was used on more than 26 million Sprint handsets, making Sprint by far the biggest user of the tool. Critics have worried the tool allows phones to double as spying devices, while the maker of the software said it is only intended to help wireless carriers improve the performance of their handsets. AT&T also said it has integrated the software into about 900,000 handsets but it is collecting data only from about 575,000 of them. The only way to completely guard your privacy when it comes to your mobile phone is to not use it.”]