Matthew Goldstein reports that's gonna leave a mark:

A former hedge fund manager who is a key cooperating witness in the Galleon insider-trading probe was "consensually recording phone calls" with potential suspects until a week before authorities arrested Galleon head Raj Rajaratnam, according to a recently unsealed court filing.
The document suggests federal authorities had wanted to keep working with Richard Choo-Beng Lee in some "covert" fashion for quite some time -- possibly even weeks or months after the October 16 arrest of Rajaratnam and five other people.

Galleon U.S. witness was taping calls for months [Reuters]