A Senate bill would offer President Obama emergency control of the Internet and may give him a kill switch" to shut down online traffic by seizing private networks -- a move cybersecurity experts worry will choke off industry and civil liberties. Details of a revamped version of the Cybersecurity Act of 2009 emerged late Thursday, months after an initial version authored by Sen. Jay Rockefeller, D-W.V., was blasted in Silicon Valley as dangerous government intrusion. "In the original bill they empowered the president to essentially turn off the Internet in the case of a 'cyber-emergency,' which they didn't define," said Larry Clinton, president of the Internet Security Alliance, which represents the telecommunications industry. The new legislation allows the president to "declare a cybersecurity emergency" relating to "non-governmental" computer networks and make a plan to respond to the danger, according to an excerpt published online -- a broad license that rights experts worry would give the president "amorphous powers" over private users. "As soon as you're saying that the federal government is going to be exercising this kind of power over private networks, it's going to be a really big issue," Lee Tien, a senior staff attorney with the Electronic Frontier Foundation.