UK Prime Minster David Cameron will be consulting with major ISPs about devising a scheme which will block adult content for UK customers. If such a content filter does materialize from the talks, it is expected to be an optional feature but also enabled by default. As a result, users who would prefer to allow sexually explicit material online must opt-out of the content blocker.

Cameron's new strategy to filter Internet pornography follows raised UK government concerns regarding child protection. Officials recently discussed the harmful effects of explicit content on youth during a parliamentary inquiry. Plans for such a system were originally discussed last year, however, talks did not lead to legislation on the matter.

The Internet Service Providers Association (ISPA) has said it will oppose any such filter because it would be simple to bypass and may offer a sense of false security to concerned parents. The ISPA is a UK-centric trade association which includes members like Google, Yahoo and Ebay.

Civil liberty and rights groups seem to mostly disagree with the filter, voicing concerns about the accidental (and inevitable) filtering of decent content and the over-simplification of the issue. "The broader consequences risk damaging legitimate businesses and undermining cyber security while further perpetuating the myth that this is an easy technological solution to a complex problem." said one such rights advocate, Nick Pickles. Others raised concerns about the slippery slope of censorship and what even a benevolent content filtering system might turn into down the road.

Interestingly, by default, UK's largest ISP British Telecommunications already filters smutty content on its cellular data service. To override the filter, you only need to know the phone number tied to your account.