On January 17, some of the most popular websites locked their doors, blacking out for hours at a time to protest the Stop Online Piracy Act, a Congressional bill that would have censored certain websites if they were found to host pirated content. Three months later, the Internet is at war with Congress again, this time over the Cyber Intelligence Sharing and Protection Act, which critics say would allow the government to snoop on private files.

They might have more of an uphill battle this time around—while some of the largest digital companies supported the SOPA protests, many of those have switched sides for CISPA, including Facebook. So while Wikipedia and Reddit are using blackouts to protest SOPA, organizations are trying to create a grassroots movement of Internet users to protest CISPA.

The bill would allow private companies to access classified government information to help protect them from cyber attacks that bring down their networks. In return, those companies would be allowed to share users' private information with the government, as long as it constitutes a "cyber threat" or relates to homeland security.

Jim Dempsey, vice president for public policy at the Center for Democracy and Technology, says that with CISPA, Congress is trying to "fundamentally change how Americans use the Internet."

Organizations such as the American Civil Liberties Union, the Electronic Frontier Foundation, and Tech Freedom have set up a "week of action" against CISPA, starting Monday. A site set up by the EFF allows users to tweet directly at their Congressional representative using the hashtags #CongressTMI and #CISPA.

The EFF keeps an eye on most legislation that could affect Internet users, but Rainey Reitman, who leads the organization's activist team, says they have to be careful about which bills they protest.

"We have to make sure they have a decent shot of passing," she says. As soon as they recognize a bill they find threatening, the organization might blog about it, but "a protest requires all our resources," she adds. "It didn't become apparent that [CISPA] was going to move forward until about a week ago."

There have already been some indications that the bill, sponsored by Reps. Mike Rogers and Dutch Ruppersberger, might be weakened before it comes to a vote. On Friday, the House Committee on Intelligence circulated a version of the bill that narrowed the language of the bill, limiting the amount of data that could be shared with the Federal Government.

Reitman says this week is an important one for the bill—next week is "Cybersecurity week" on Capitol Hill, so the bill is likely to be put to a vote.