On local news stations across the United States last month, dozens of anchors gave the same speech to their combined millions of viewers.

It included a warning about fake news, a promise to report fairly and accurately and a request that viewers go to the station’s website and comment “if you believe our coverage is unfair.”

It may not have seemed strange to individual viewers. But Timothy Burke, the video director at Deadspin, had read a report last month from CNN, which quoted local station anchors who were uncomfortable with the speech.

Mr. Burke tracked down the stations and found when each had aired what he called a “forced read.”

Then he stitched together the various broadcasts to create a supercut of anchors eerily echoing the same lines:

“The sharing of biased and false news has become all too common on social media.”