Two days after Facebook unveiled simplified privacy controls, the furore over its perceived missteps is not dying down.

On Friday Congressman John Conyers, head of the House Judiciary Committee, sent a letter to Facebook asking it to cooperate with federal regulators looking into its privacy policies. Mr Conyers also sent a similar letter to Google, which is facing scrutiny after it admitted collecting wifi data.

Mr Conyers’ letter followed a conference call on Thursday during which several privacy advocates who had given Facebook credit for their effort on Wednesday took a harder line against the company and called for federal regulation of social networking sites.

According to the Associated Press, Mr Conyers asked Facebook “to provide details about its sharing of  member information with third parties and about its privacy policies.”

Mr Conyers did not say that the House Judiciary Committee was beginning an investigation. But several privacy groups have lodged complaints with the Federal Trade Commission, which are under review.

On Thursday’s call John Simpson of Consumer Watchdog said Facebook’s changes were largely superficial, and that its actions represent a “Silicon Valley mindset” that encourages pushing the envelope when it comes to privacy.

“I don’t think we have any reason to trust the company now based on their past record,” he said. “There’s a pretty clear need for federal regulation at the FTC.”

Also on the call was Jeff Chester of the Center for Digital Democracy, who said the company needed to make more meaningful changes. “The whole process raises questions about Facebook’s commitment to privacy,” he said. “Congress needs to address Facebook in its forthcoming hearings on privacy.”

Oftentimes advocacy groups seem to be screaming into the wind. This time, at least one congressman was listening.