YouTube has been subject to various controversies since its creation in 2005.
It has become one of Google's fastest-growing operations in terms of sales by simplifying the process of distributing video online but putting in place few limits on content.
However, parents, regulators, advertisers and law enforcement have become increasingly concerned about the open nature of the service.
They have contended that Google must do more to banish and restrict access to inappropriate videos, whether it be propaganda from religious extremists and Russia or comedy skits that appear to show children being forcibly drowned.
Child exploitation and inappropriate content
By the end of last year YouTube said it had removed more than 50 user channels and has stopped running ads on more than 3.5 million videos since June.
In March last year, a disturbing Peppa Pig fake, found by journalist Laura June, shows a dentist with a huge syringe pulling out the character's teeth as she screams in distress.
Mrs June only realised the violent nature of the video as her three-year-old daughter watched it beside her.
Hundreds of these disturbing videos were found on YouTube by BBC Trending back in March.
By the end of last year YouTube said it had removed more than 50 user channels and has stopped running ads on more than 3.5 million videos since June. One of the deleted videos was the wildly popular Toy Freaks YouTube channel featuring a single dad and his two daughters
All of these videos are easily accessed by children through YouTube's search results or recommended videos.
YouTube has been getting more stringent about deleting videos. One example is the wildly popular Toy Freaks YouTube channel featuring a single dad and his two daughters that was deleted last year.
Although it's unclear what exact policy the channel violated, the videos showed the girls in unusual situations that