I was recently sent a link for this article, which on first reading might sound almost sensible but there are a couple of issues / questions.
Firstly they do not define what 'adult content' is, without this it is not possible to know what they will and won't block. Secondly they do not say how they intend to do the blocking.
This will clearly not be real time blocking and will require a list of urls to block or similar, eg the IWF block list. We already know that this sort of blocking does not work as web site owners will simply keep changing the urls. Also accessing the sites via a VPN or proxy will also render the list useless.
The technology to do this right simply doesn't exist. If I put up a pornographic video on my website, the current suggested blocking methods will NOT block access to this because the blocking is not real time inspection.
Trying to block access to adult content using this method is like trying to nail water to a tree, it is just a waste of time and effort and will prove ultimately useless.
Stop trying to force ISPs and other companies to be parents to the children of this country, force the parents to be parents. Parents are quick enough to blame ISPs and demand they do more, but there are already solutions that are already widely available, many are offered for free, but require parents to be parents.
This comes back to the same issue time and time again, educate people, support people and provide them with tools to make better choices, do not legislate for stupidity or laziness!