In the United States, if someone puts up a really vicious Yelp review of a restaurant — one that’s wildly libelous, for example — the restaurant could sue the person who posted the review but couldn’t go after Yelp.

That’s thanks to a provision of U.S. law known as Section 230 of the Communications Decency Act.

That same protection has been added to the United States-Mexico-Canada Agreement, the trade deal that replaces the North American Free Trade Agreement.

Supporters say it will extend an American-style, business-friendly environment to Canada and Mexico. Opponents say tech companies don’t need more protection.

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