https://www.reuters.com/article/us-britain-election-facebook/facebook-says-doctored-uk-election-clip-wouldnt-break-its-ad-rules-idUSKBN1XH2MO

Facebook said on Thursday that a doctored video shared by Britain's governing Conservatives would not have broken its rules on political advertising if it had run as a paid-for ad, and suggested the video had enriched public debate.