and assaulting two federal agents. the younger of the two al qaeda sympathizers was planning to hit a target in new york city with explosives. the older brother financed and encouraged the plot. the attacks on the federal marshals happened while the brothers were in custody. lawyers on both sides agreed to a prison term of 32 years for the younger brother and 17 years for the older. it appears big brother really is listening. chief intelligence correspondent katherine har raj is here to tell us more a coordinated federal effort to use your cell phone to track you. good evening katherine. reporter: the feds say they are targeting criminals but anyone s cell phone is vulnerable. the program run through the u.s. marshals service scoops up vast imagine of data and scans it before identifying the device and owner. critics question whether the data collection is constitutional. these devices can t help but also sweep in information about thousands, maybe tens of thousands of completely