By Brendan Sasso - 01/07/13 04:29 PM EST
Sens. Ron Wyden (D-Ore.) and John Kerry (D-Mass.) have also criticized the FTC for revealing sensitive information.
An FTC spokeswoman acknowledged that the agency had received the letter but had no further comment.
The letter was first reported by technology news site Mashable.
Issa sent a separate letter to the FTC last month criticizing its handling of the Google case. He mentioned unauthorized leaks to the media as one of several issues that gave him concern.