YouTube has removed two videos of California doctors ... Dan Erickson and Artin Massihi of Bakersfield, California [which] downplayed the risk of the coronavirus and asserted that stay-at-home measures were unnecessary. Facebook, however, has not removed the doctors' videos. The different reactions of YouTube and Facebook highlight the challenges of moderating high-stakes misinformation as it goes viral, especially when it is considered to be expert opinion. The video removed by YouTube showed a one-hour news conference livestreamed by local media, including NBC and ABC affiliates in Bakersfield. By Wednesday, the video had been seen at least 15 million times. Erickson and Massihi, owners of several urgent care centers in the area, presented data from 5,213 COVID-19 tests. The data, they claimed, showed that the coronavirus was widespread in the community already but had caused few deaths. Their data, they said, supported the need to rethink state stay-at-home measures. Furthermore, Erickson ... claimed that COVID-19 death numbers were inaccurate, citing other unnamed doctors in Wisconsin and California who he said had told him that they were urged to list the disease as a cause of death even if it was unrelated. "The only justification for taking it down was that the two physicians on screen had reached different conclusions from the people currently in charge," said Fox News host Tucker Carlson. Massihi posted a video to his personal Facebook page Tuesday thanking supporters while insisting that their comments were meant only to share their own data, not to drive national or even state policy.