To an extent that nobody else has managed, the copyright industries have been able to bake protection for their rights into the very infrastructure of the internet. The challenge of limiting illicit file sharing is similar to many of the other difficult issues – like addressing offensive content, removing defamatory posts, or limiting the flow of misinformation – in internet regulation. How do you control what users do online without directly going after individual users? Legal actions against individuals are expensive; they only really make sense in high value cases. Changing the behavior of many individuals on a large scale is much more difficult, whether it’s users sharing copyrighted music and films or people using the internet to harass others. Any effective answer has to involve technology companies and internet intermediaries in some way, because they have the power to influence large numbers of users through their design choices and policies.