This article has had me wondering for a few months...
http://www.wired.com/news/politics/0,1283,46747,00.html
Anti-Attack Feds Push Carnivore
By Declan McCullagh
Sep. 12, 2001
WASHINGTON -- Federal police are reportedly increasing Internet surveillance after Tuesday's deadly attacks on the World Trade Center and the Pentagon.
Just hours after three airplanes smashed into the buildings in what some U.S. legislators have dubbed a second Pearl Harbor, FBI agents began to visit Web-based, e-mail firms and network providers, according to engineers at those companies who spoke on condition of anonymity.
An administrator at one major network service provider said that FBI agents showed up at his workplace on Tuesday "with a couple of Carnivores, requesting permission to place them in our core, along with offers to actually pay for circuits and costs."
The person declined to say for publication what the provider's response was, "but a lot of people" at other firms were quietly going along with the FBI's request. "I know that they are getting a lot of 'OKs' because they made it a point to mention that they would only be covering our core for a few days, while their 'main boxes were being set up at the Tier 1 carriers' -- scary," the engineer said.
[...]
Has anyone heard anything saying that these Carnivore/DCS-1000 units have been removed, or are they still recording data?