Er... just because you can't prevent something by technical means, doesn't mean you shouldn't try to prevent it by social means. For example: There's no techni

Er... just because you can't prevent something by technical means, doesn't mean you shouldn't try to prevent it by social means. For example: There's no technical way I can prevent you from slandering me, short of preventing all of your speech. However if you do slander me, and I find out about it then I can take you to court. The nopin setting just enforces a gentlemans agreement between Pinterest and the site in question. If the Pinterest user really wants to share that picture, all they have to do is copy the link and do it manually.