To protect children online, more companies and governments are forcing users to prove how old they are.
Richard Errington clicked to stream a science-fiction film from his home in Britain last month when YouTube carded him.
The site said Mr. Errington, who is over 50, needed to prove he was old enough to watch “Space Is the Place,” a 1974 movie starring the jazz musician Sun Ra. He had three options: Enter his credit card information, upload a photo identification like a passport or skip the video.
“I decided that it wasn’t worth the stress,” he said.