A trade group representing Facebook, Google, Yahoo and other tech and communications companies has come down heavily against the Cybersecurity Information Sharing Act of 2015, a controversial bill in the U.S. that is intended to encourage businesses to share information about cyberthreats with the government.

The Computer & Communications Industry Association claims that the mechanism CISA prescribes for the sharing of cyberthreat information does not adequately protect users’ privacy or put an appropriate limit on the permissible uses of information shared with the government.

The bill, in addition, "authorizes entities to employ network defense measures that might cause collateral harm to the systems of innocent third parties," the CCIA said in a blog post Thursday.

CISA, which would give businesses immunity from customer lawsuits when they share cyberthreat data with the government, is due for consideration by the U.S. Senate in the coming weeks.

Critics of the bill are concerned that the provisions of the bill could be used by companies to hand over customers’ personal data to government intelligence agencies such as the National Security Agency. Cyberthreat information-sharing may not have prevented several recent attacks on government agencies, according to experts.

Civil rights groups opposed to the bill got an unexpected ally in the U.S. Department of Homeland Security, which warned in July about the privacy implications of the bill.

The authorization in CISA to share cyberthreat data with any federal agency, notwithstanding any other provision of law, could impact key privacy provisions, including those in the Stored Communications Act that limit the disclosure of the content of electronic communications to the government by providers, wrote Alejandro N. Mayorkas, deputy secretary of the DHS in a letter to Senator Al Franken, a Democrat from Minnesota, who opposes the legislation.

DHS also warned that the proposed information sharing system with multiple agencies would slow down responses to a cyberthreat, and advocated a more centralized mechanism for sharing data through the National Cybersecurity and Communications Integration Center (NCCIC), a non-law enforcement, non-intelligence center focused on network defense activities, that would scrub private information from the data before sending it to other agencies.

The tech industry holds that current rules already permit companies to share cyberthreat indicators with the government, and "should not be discounted as useful existing mechanisms." CCIA approves of the goal of building a more robust mechanism for information sharing, but does not want it to come at the expense of user privacy.

A privacy group last month started an online protest, called YouBetrayedUs, after a letter by the BSA | The Software Alliance of software vendors to Congress appeared to endorse CISA. The letter had urged action by the House of Representatives and the Senate on five pending legislative efforts, including CISA, but BSA later clarified that it had not endorsed any specific legislation in its current form. “The letter clearly was a mistake and doesn’t imply CISA support. We need to clarify. I’m against it,” Marc Benioff, CEO of Salesforce.com said in a tweet.