UK: How do ISPs Implement Network Based Parental Control Service?

Ofcom has "published a report for Government outlining measures the UK's largest internet service providers have put in place to help parents protect children from harmful content online. This follows an agreement between the Government and BT, Sky, TalkTalk and Virgin Media, the four largest fixed line internet service providers (ISPs), announced in July 2013 [see "UK to Enforce Opt Out Network