Spamhaus has been sued—multiple times, I believe—for publishing DNS-based lists used to block email from known spammers.

For instance: https://reason.com/volokh/2020/07/27/injunction-in-libel-cas... (That was a default judgment, though, which means Spamhaus didn't show up, probably due to jurisdictional questions.)

The first step in filing a libel lawsuit is demanding a retraction from the publisher. I would imagine Google's lawyers respond pretty quickly to those, which is why SafeBrowsing hasn't been similarly challenged.