YouTubers including PewDiePie were paid tens of thousands of dollars to give video games positive reviews, it's been claimed.
Warner Bros, makers of Shadow of Mordor, has reached a settlement with the Federal Trade Commission (FTC) after they were accused of hiding the payments from people.
The FTC, a consumers rights organisation, stated Warner Bros had deceived customers by paying YouTubers to promote the game without admitting it.
The company is now banned from hiding similar deals in the future and from pretending sponsored videos are the work of independent producers.
"Consumers have the right to know if reviewers are providing their own opinions or paid sales pitches," said Jessica Rich from the FTC.
Companies like Warner Bros need to be straight with consumers in their online ad campaigns."
According to the FTC, Warner Bros paid some YouTubers tens of thousands of dollars to promote Shadow of Mordor.
They also gave them a free, advance-release version of the game and told them how to promote it.
It also claims YouTubers were advised to put the video's sponsored status under the "Show More" section.
That means the information wouldn't have been visible on videos watched through Twitter and Facebook.