Others worry about possible repercussions in two additional areas: innovation and economics. CDT's John Morris fears that some day entrepreneurs may have to hire lawyers and navigate FBI labyrinths to win approval for new devices before they can bring them to market.

"That is guaranteed to slow down innovation on the Internet -- and even more guaranteed to drive innovation offshore," says Morris

The full-text FCC ruling, which is scheduled to released later this month, does not cover technical issues, only compliance. The commission plans to develop its technical guidelines within the next two months and release a second order.

In the broader perspective, some critics see this rule expansion as a result of law enforcement’s misunderstanding of broadband technologies. They argue that a qualitative difference exists between traditional telephone networks, which route communications through central hubs, and VOIP systems, such as Skype, that employ a peer-to-peer model. People may use VOIP as a substitute for land-line calls (which is the legal reasoning behind the FCC’s ruling) -- but the underlying technologies are vastly different: VOIP is a portable technology that’s untethered from underlying networks and sometimes doesn't even involve a fixed telephone number.

"I would hope that there’s no expectation that you’re going to be able to route all voice communications through central control points in order to accommodate the potential need for wiretapping," says Mark Uncapher, senior vice president and counsel for the Information Technology Association of America. "It would be a real impediment to have to operate that way."   

Uncapher and other VOIP advocates point out that, ironically, by focusing on CALEA, law enforcement agencies may be missing a more promising quarry: the new technology’s digital storage potential, which could change the nature of surveillance.

"Law enforcement is used to looking at it in a certain way. With VOIP we need to get beyond that," says Jim Kohlenberger, executive director of the Voice on the Net Coalition, which represents companies ranging from Skype to Intel to AT&T. “Rather than having those guys out there in truck with cold coffee and headphones on, imagine if they could automatically get that conversation right to their desktop, stored and routed just like e-mail. It would give them better and more capabilities.”

When the full FCC proposal is released later this month, a court battle seems imminent. If a legal challenge is successful, federal law enforcement agencies may well petition Congress to pass dedicated legislation to accomplish the same end.

Meanwhile, the shifting clouds of CALEA hang over broadband providers. As the CDT has observed in its legal brief: "Regulatory uncertainty is the enemy of innovation."