YouTube videos featuring alcohol nearly always promote the "fun" side of drinking and are viewed by millions of users which may include teenagers and children, scientists say.
Researchers from the University of Pittsburgh in the US looked at 137 YouTube videos that featured alcohol brands popular with underage drinkers - from beer to vodka to cognac. Together, the videos had been viewed nearly 97 million times.
Most often - 40 per cent of the time - the videos were traditional advertisements.
Others were "guides," in which a host showcased a particular alcohol, discussing its merits and offering serving suggestions.
About 10 per cent featured men showing off their "chugging" prowess, according to the study published in the Journal of Studies on Alcohol and Drugs.
There is no way of knowing how many of those millions of viewers were underage kids, according to lead researcher Brian Primack, from the University of Pittsburgh.
"Our aim is not to say we should be censoring this. However, knowing about this content should help us develop appropriate educational programmes," said Primack.
The alcohol ads were usually uploaded by ordinary YouTube users, rather than manufacturers. However, the industry is never completely out of the picture, he said.
Companies create their ads to be funny or otherwise engaging, and that may be partly with the hope that people will share them on social media.
"We are not suggesting that young people should never see these videos or that parents say, Youre never using the Internet again," Primack said.
Instead, he suggested that parents help their kids be more savvy about alcohol advertising.
They could point out how companies can try to manipulate people - by, for instance, portraying alcohol as a key ingredient to socialising and having fun.
"Parents can be important purveyors of media literacy. They can help their kids become more critical thinkers about what they see in ads," Primack said.
