Although the scope of surveillance conducted under the Foreign Intelligence Surveillance Act remains shrouded in secrecy, newly disclosed documents show the costs one company charges the government to eavesdrop on customers.

Comcast, which is among the nation's largest telecommunication companies, charges $1,000 to install a FISA wiretap and $750 for each additional month authorities want to keep an eye on suspects, according to the company's Handbook for Law Enforcement. Secrecy News obtained the document and published it Monday.

"I was actually surprised that this was such a routine transaction that it would have a set fee," said Steven Aftergood, director of the Federation of American Scientists' Project on Government Secrecy.