Some YouTube users were seeing error messages on the site Friday morning.
An "internal service error" message that appeared around 9 a.m. ET showed a monkey with a hammer and code.
The website DownDetector, which tracks reports of service errors, received thousands of reports of problems on the site Friday morning around that time.
YouTube hasn't immediately tweeted about the issue. The video streaming site gets the second most traffic of any website on the internet behind Google, according to analytics site Alexa.