President Trump posted a heavily edited video attacking House Speaker Nancy Pelosi this week, sparking a feud highlighting the gray areas that persist about what manipulated content is permissible on social media.

In the video, Mrs. Pelosi (D., Calif.) appeared to be ripping up a copy of Mr. Trump’s State of the Union address during the points of his remarks when U.S. citizens and military members were being honored with applause. Mrs. Pelosi only tore up the script once, at the end of the speech.

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