The bill would grant President Obama the power to declare a “national cyber-emergency” at his discretion and force private companies tied to the Web, including Internet service providers and search engines, to take action in response—moves that could include limiting or even cutting off their connections to the World Wide Web for up to 30 days.

While the bill’s sponsors say it is intended to create a shield to defend the United States and its largest companies from the growing threat of cyberattacks, civil-liberties activists tell The Daily Beast they fear the bill could give the White House the ability to effectively shut down portions of the Internet for reasons that could prove to be politically inspired.

“We have seen through recent history that in an emergency, the Executive Branch will interpret grants of power very broadly,” said Gregory Nojeim of the Center for Democracy and Technology, a group that promotes Internet freedom. He said the bill, which he described as moving “at lightning speed in congressional terms,” was too loosely worded in its definition of which companies would be regulated and what they would be required to do in an emergency.