The FBI is renewing its request for new Internet surveillance laws, saying technological advances hinder surveillance and warning that companies should be required to build in back doors for police.

"We must ensure that our ability to obtain communications pursuant to court order is not eroded," FBI director Robert Mueller told a U.S. Senate committee this week. Currently, he said, many communications providers "are not required to build or maintain intercept capabilities."

Mueller's prepared remarks reignite a long-simmering debate pitting the values of privacy, limited government, and freedom to innovate against law enforcement requests that often find a receptive audience on Capitol Hill. Two days ago, for instance, senators delayed voting on a privacy bill that would require search warrants for e-mail after sheriffs and district attorneys objected.

'Going Dark' timeline June 2008: FBI Director Robert Mueller and his aides brief Sens. Barbara Mikulski, Richard Shelby, and Ted Stevens on "Going Dark." June 2008: FBI Assistant Director Kerry Haynes holds "Going Dark" briefing for Senate appropriations subcommittee and offers a "classified version of this briefing" at Quantico. September 2008: FBI completes a "high-level explanation" of CALEA amendment package. May 2009: FBI Assistant Director Rich Haley briefs Senate Intelligence committee and Mikulsi staffers on how bureau is "dealing with the 'Going Dark' issue.'" Mikulski plans to bring up "Going Dark" at a closed-door hearing the following week. November 2008: FBI Assistant Director Marcus Thomas, who oversees the Quantico-based Operational Technology Division, prepares briefing for President-Elect Obama's transition team. December 2008: FBI intelligence analyst in Communications Analysis Unit begins analysis of VoIP surveillance. February 2009: FBI memo to all field offices asks for anecdotal information about cases where "investigations have been negatively impacted" by lack of data retention or Internet interception. March 2009: Mueller's advisory board meets for a full-day briefing on Going Dark. April 2009: FBI distributes presentation for White House meeting on Going Dark. April 2009: FBI warns that the Going Dark project is "yellow," meaning limited progress, because of "new administration personnel not being in place for briefings." April 2009: FBI general counsel's office reports that the bureau's Data Interception Technology Unit has "compiled a list of FISA dockets... that the FBI has been unable to fully implement." FISA is the Foreign Intelligence Surveillance Act. May 2009: FBI e-mail boasts that the bureau's plan has "gotten attention" from industry, but "we need to strengthen the business case on this." July 2010: FBI e-mail says the "Going Dark Working Group (GDWG) continues to ask for examples from Cvber investigations where investigators have had problems" because of new technologies. September 2010: FBI staff operations specialist in its Counterterrorism Division sends e-mail on difficulties in "obtaining information from Internet Service Providers and social-networking sites."

In May, CNET disclosed that the FBI is asking Internet companies not to oppose a proposed law that would require firms, including Microsoft, Facebook, Yahoo, and Google, to build in back doors for government surveillance. The bureau's draft proposal would require that social-networking Web sites and providers of VoIP, instant messaging, and Web e-mail alter their code to ensure their products are wiretap-friendly.

An FBI representative declined to respond to requests for comment yesterday afternoon. (Mueller submitted prepared remarks for Wednesday's hearing but, because of a dental emergency, did not attend. Kevin Perkins, the FBI's associate deputy director, filled in for him.)

Mueller warned: "Because of this gap between technology and the law, law enforcement is increasingly unable to access the information it needs to protect public safety and the evidence it needs to bring criminals to justice."

The draft legislation is one component of what the FBI has internally called the "National Electronic Surveillance Strategy" and has publicly described as its "Going Dark" problem. Going Dark has emerged as a serious effort inside the bureau, which employed 107 full-time equivalent people on the project as of 2009, commissioned a RAND study, and sought extensive technical input from its secretive Operational Technology Division in Quantico, Va. The division boasts of developing the "latest and greatest investigative technologies to catch terrorists and criminals."

The Electronic Frontier Foundation, a digital rights group in San Francisco, says there's no need to expand wiretapping law for the Internet. EFF staff attorney Hanni Fakhoury told CNET:

New technologies have provided the FBI with unprecedented capabilities to conduct surveillance, making it faster and easier for the government to take a look at the increasingly intimate online portrayal of the lives of Americans. No longer does the government face anonymous pay-phones or the challenge of physically tracking a person's location through time-consuming manual surveillance. Plus, with more and more conversations documented by some sort of electronic record, it seems to us that law enforcement has had no problem getting access to digital material from telecommunications providers with little judicial oversight or scrutiny. To ensure that the laws keep pace with new technology, we must ensure that the Fourth Amendment and due process remain paramount.

The FBI's proposal would amend a 1994 law, called the Communications Assistance for Law Enforcement Act, or CALEA, that currently applies only to telecommunications providers, not Web companies. The Federal Communications Commission extended CALEA in 2004 to apply to broadband networks.

It's not exactly clear how much of the FBI's problems in conducting surveillance arise from wireless communications, encryption, social networks, or VoIP; the bureau has not been eager to be specific. Microsoft's Skype service has worked with law enforcement to make online chats and other user information available to police, the Washington Post reported in July.

An internal FBI strategy document from 2007 recently posted by Cryptome.org refers to "proposed amendments" to CALEA that would codify the authority of police to "process a subject's communications traffic, including IP/packet-based communications."