YouTube suspends Rand Paul for a week over a video disputing the effectiveness of masks.

YouTube on Tuesday removed a video by Senator Rand Paul of Kentucky for the second time and suspended him from publishing for a week after he posted a video that disputed the effectiveness of wearing masks to limit the spread of the coronavirus.

A YouTube representative said the Republican senator’s claims in the three-minute video had violated the company’s policy on Covid-19 medical misinformation. The company policy bans videos that spread a wide variety of misinformation, including “claims that masks do not play a role in preventing the contraction or transmission of Covid-19.”

“We apply our policies consistently across the platform, regardless of speaker or political views, and we make exceptions for videos that have additional context such as countervailing views from local health authorities,” the representative said in a statement.

In the video, Mr. Paul says: “Most of the masks you get over the counter don’t work. They don’t prevent infection.” Later in the video, he adds, “Trying to shape human behavior isn’t the same as following the actual science, which tells us that cloth masks don’t work.”

In fact, masks do work, according to the near-unanimous recommendations of public health experts.

On Tuesday, Twitter suspended Representative Marjorie Taylor Greene, Republican of Georgia, for seven days after she posted that the Food and Drug Administration should not give the coronavirus vaccines full approval and that the vaccines were “failing.”

On Twitter, Mr. Paul called his suspension “a badge of honor” and blamed “left-wing cretins at YouTube,” while linking to an alternative site to watch the video.