Does that mean porn is watched by 77% fewer people or does that mean it is watched elsewhere? It may just lead to a greater exposure to malware of the UK.
Obviously not, a lot of them just don't want to identify themselves. But having worked in IT for 25 years and knowing how free some people are to use their government e-mail to sign up at porn websites, I wonder even if 50% are underage, that's a huge number.
It's not 1999 anymore. Stop going to sketchy sites to watch porn.