Facebook pulled an ad over the weekend that falsely suggested that Sen. Lindsey Graham had endorsed the Green New Deal.

The big picture: Facebook hasn't changed its policy allowing political candidates to lie at will in advertisements. In this case, it was a third-party political action committee making the allegation — and Facebook doesn't give such groups the same exemption as candidates themselves.

Between the lines: When CEO Mark Zuckerberg testified last week before a House committee, Rep. Alexandria Ocasio-Cortez asked if she could run an ad claiming Republicans had supported, for example, the Green New Deal. Zuckerberg said she probably could.

A third-party group decided to do just that, suggesting Graham had endorsed the environmental proposal.

Why it matters: Facebook's free pass for political lies has prompted legislators like Ocasio-Cortez and presidential candidate Sen. Elizabeth Warren to test the policy's limits, but so far, there don't seem to be any — as long as you're a politician.