CISPA would let Internet companies monitor and collect any user information they think poses a threat to their networks or systems. The bill would also let these companies share the collected information with the NSA and other federal agencies. Companies that share such information would enjoy a high degree of legal immunity for their actions.

Privacy advocates, rights groups and several have expressed over the information sharing bill, and have said it would enable unprecedented surveillance of online activities under the pretext of cybersecurity.

Groups such as the Electronic Frontier Foundation and the American Civil Liberties Union have noted that the bill would allow companies to collect and share all kinds of personal information with the government, without any judicial oversight. They have claimed the bill will allow government and law enforcement agencies to do an end-run around the privacy protections offered by statutes such as the Federal Wiretap Act and the Electronic Communications Privacy Act.

One aspect of the bill that has raised particular alarm is a provision that would allow information collected for cybersecurity reasons to be also used by the NSA and others agencies for a wide range of unrelated national security purposes.

The mounting outcry against the bill has prompted some proposed revisions by members of the House Intelligence Committee. The proposed amendments include one that would narrow the definition of the information that can be collected and shared with the government. Another prohibits the bill to be used for monitoring copyright and intellectual property violations. A third one would require an annual review of how shared information is used by the NSA and other agencies.