Livingstone and Lunt believe that media is generally very hard to regulate
IPSO - IndependentPressStandardsOrganisation - regulates the press and broadcasters. Form of regulation.
Technology has made regulation incredibly hard to do. It used to be the case that you could be ID'd for looking under the age of 18 and wanting to buy an 18+ film.
The BBFC - the British Board of Film Classification - is responsible for the classification of films and video games. They have no power to ban films and video games online.
Downloading, streaming, piracy, You Tube etc means people can bypass controls like age certificates
The vast nature of the internet (Billions of users) and the fact that it is a global network means that it is very difficult to control. It could take a while for a pirated or innaproprioate video to be taken down.
Powerful companies can avoid regulations
Eg. NewsCorp, have in the past broken rules of the regulation of newspapers. It resulted in the "News Of The World" paper being shut down.
Ofcom: The UK's communications regulator, responsible for ensuring that the UK's communications infrastructure is fit for purpose.
PEGI: The British video game rating board that is responsible for rating video games for the UK market.