Wiretapping is common practice, here's how much carriers charge law enforcement agencies for it

Wiretaps cost hundreds of dollars per target every month, generally paid at daily or monthly rates. To wiretap a customer's phone, T-Mobile charges law enforcement a flat fee of $500 per target. Sprint's wireless carrier Sprint Nextel requires police pay $400 per "market area" and per "technology" as well as a $10 per day fee, capped at $2,000. AT&T charges a $325 activation fee, plus $5 per day for data and $10 for audio. Verizon charges a $50 administrative fee plus $700 per month, per target.

Data requests for voicemail or text messages cost extra. AT&T demands $150 for access to a target's voicemail, while Verizon charges $50 for access to text messages. Sprint offers the most detailed breakdown of fees for various kinds of data on a phone, asking $120 for pictures or video, $60 for email, $60 for voice mail and $30 for text messages.

All four telecom firms also offer so-called "tower dumps" that allow police to see the numbers of every user accessing a certain cell tower over a certain time at an hourly rate. AT&T charges $75 per tower per hour, with a minimum of two hours. Verizon charges between $30 and $60 per hour for each cell tower. Sprint demands $150 per cell tower per hour, and Sprint charges $50 per tower, seemingly without an hourly rate.