> In the UK, ISPs are legally forced to block certain types of websites, such as those hosting copyright-infringing or trademarked content. Some ISPs also block other sites at their discretion, such as those that show extremist content, adult images, and child pornography. These latter blocks are voluntary and are not the same across the UK, but most ISPs usually tend to block child abuse content.<p>It does give the lie to the "for the children" argument when blocking copyright infringement is mandatory and banning child porn is optional.