The House of Representatives passed the Fight Online Sex Trafficking Act (or FOSTA), a measure closely related to the SESTA bill introduced in the Senate last year. The measure passed on a 388-25 vote, with 14 Republicans and 11 Democrats voting in opposition.

The bill would make websites criminally liable for hosting ads and other content linked to a sex-trafficking enterprise. The result would be a major exception to existing Safe Harbor provisions, and has been opposed by groups like the EFF and ACLU for its potential impact on online speech. In a tweet after the vote, EFF called FOSTA’s passage “a dark day for online communities.”

BREAKING: The House has passed FOSTA 388 - 25. This is a dark day for online communities. We can't let the Senate pass this censorship bill. — EFF (@EFF) February 27, 2018

The proposed law has split the tech world, with Oracle, IBM and the Internet Association cheering on the new measures. Notably, companies like Google and Facebook have largely remained silent, although they would be significantly impacted if the bill became law. Shortly after SESTA was introduced, the Wikimedia Foundation argued that user-submission projects like Wikipedia simply couldn’t exist without Section 230’s strong Safe Harbor provisions.

The latest version of the bill also ran into some unexpected constitutional problems. Shortly before the House vote, the Department of Justice sent a letter to the bill’s sponsors raising concern that the retroactive measures in FOSTA — which allows for prosecutions based on conduct before the date of the bill’s enactment — might violate the constitution’s Ex Post Facto clause. It’s unclear if the language of the bill has been altered to accommodate the objection, but it could provide grounds for a legal challenge in the future absent corrective action by the Senate.