Facebook is in the midst of its worst scandal since Cambridge Analytica. CEO Mark Zuckerberg has been hammered by presidential candidates, members of Congress, fellow tech moguls and virtually every major newspaper, magazine and television network. Hundreds of Facebook employees have signed a petition calling for him to change course.

What did Zuckerberg do to deserve this avalanche of criticism? Cave to Chinese censorship pressure, like some NBA players? Walk away from U.S. defense contracts for ideological reasons, like Google did last year?

No, the scandal is that Zuckerberg said two weeks ago that Facebook is committed to supporting free expression. Most scandalously, he said his company, like broadcast stations, won't fact-check candidate election ads. Instead it will allow disputed claims to be debated by the public and press in America's democratic tradition.

This has many in politics and the media up in arms because they think it could re-elect President Donald Trump in 2020, and they've wasted no time signaling to Zuckerberg that they'll blame him if Trump wins. We doubt Zuckerberg favors Trump politically.

Yet the company is thinking beyond the current frenzied political environment. Politicians have been lying about one another for hundreds of years, and dragging Facebook into the election circus will damage the company's credibility in the eyes of millions and undermine faith in the electoral process.

The media anger about Zuckerberg's free-speech policy is especially odd. Shouldn't reporters want to know what candidates are saying so they can dissect and report on it?

Instead journalists are offering sophisticated-sounding arguments for why political speech should be controlled by tech companies. One popular argument is that Facebook's algorithm rewards appeals to emotion so legitimate debate can't take place. Yet political advocacy in the U.S. has always included emotional appeals. If Facebook's algorithms favor polarizing content, that's a separate debate.

FROM AN EDITORIAL IN THE WALL STREET JOURNAL