Evaluating SOPA: who should enforce IP online?

The Stop Online Piracy Act, or SOPA, was a highly controversial proposal put to US Congress to enable the enforcement of copyright and trade mark law against foreign 'rogue' websites. SOPA would have enlisted a range of new intermediaries in the online enforcement 'war': in particular, domain name servers, credit card providers and online advertising service providers. This article outlines the proposals that were included in SOPA and critically analyses the simplistic 'least cost avoider' reasoning that justifies enlistment of these intermediaries on the basis that there is an online enforcement problem that they could assist in reducing. Although SOPA itself is politically dead, ideas embodied in it are likely to recur in some form in the future. It is therefore worth critically examining what was proposed.