The world's most popular video-sharing site said it has started implementing stricter standards for mature content. "While videos featuring pornographic images or sex acts are always removed from the site when they're flagged, we're tightening the standard for what is considered 'sexually suggestive,'" YouTube said on its blog. "Videos with sexually suggestive (but not prohibited) content will be age-restricted, which means they'll be available only to viewers who are 18 or older."
In addition, YouTube will start "demoting" videos deemed sexually suggestive and those that contain profanity from its most viewed and top favorited lists.
Also, the site will select thumbnail images for videos via an algorithm rather than auto-generating them at predefined points in a video. That will remove the possibility of gaming the system, as some creators have done by including sexy images at those predefined points to become alluring thumbnails.