The Dell company sells computer equipment retail over the Internet. It has its Canadian head office in Toronto and a place of business in Montreal. On April 4, 2003, the order pages on its English-language Web site indicated prices of $89 rather than $379 and of $118 rather than $549 for two models of handheld computers. On April 5, on being informed of the errors, Dell blocked access to the erroneous order pages through the usual address. D, circumventing the measures taken by Dell by using a deep link that enabled him to access the order pages without following the usual route, ordered a computer at the lower price indicated there. Dell then posted a price correction notice and at the same time announced that it would not process orders for computers at the prices of $89 and $118. When Dell refused to honour D’s order at the lower price, the Union des consommateurs and D filed a motion for authorization to institute a class action against Dell. Dell applied for referral of D’s claim to arbitration pursuant to an arbitration clause contained in the terms and conditions of sale, and dismissal of the motion for authorization to institute a class action. The Superior Court and the Court of Appeal held, for different reasons, that the arbitration clause could not be set up against D.