Forbes has an interesting summary of recent ACLU work to expose the business of cellphone taps in America

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.

…an AT&T spokesperson referred me to the company’s privacy policy, pointing out a specific line that reads, “We do not sell your personal information to anyone for any purpose. Period.”

That claim is “simply misleading,” says Catherine Crump, an attorney with the ACLU who coordinated the group’s FOIA project. “That’s a curious definition of ‘sell,’ given that they seem to be charging money for people’s information on a regular basis and handing it over to law enforcement agencies around the country.”

The data is obviously full of clues of how to make a cellphone tap as expensive as possible. It also reveals that the carriers vary widely in their definition of operational “cost”.

In any case the ACLU has an excellent point. Although access to data may carry a cost burden that carriers need to recoup, they directly assign a value and sell access to data instead of covering their costs indirectly.