|Prof Posner and his cat|
The question of whether final injunctive relief is a guaranteed remedy was addressed but not answered in the presentation by Joel Smith and Christopher Sharp of Herbert Smith Freehills. Presumably they wish to continue arguing both ways depending on the client.
So what do we need to look at in the UK if we want to follow the US route. The consensus seems to be that you start with Lord Cairn's Act and the Shelfer exception, progress to a detailed study of Article 3 and 12 of the Enforcement Directive (2004/48/EC) which was implemented in the UK by a Statutory Instrument that doesn't think it changed the law but might have. Then ensure your argument can be reconciled with TRIPS which says that The judicial authorities shall have the authority to order a party to desist from an infringement.
The Enforcement Directive offers the best opportunities: Article 3(2) is the general obligation that provides Those measures, procedures and remedies shall also be effective, proportionate and dissuasive and shall be applied in such a manner as to avoid the creation of barriers to legitimate trade and to provide for safeguards against their abuse. Article 12 allows Member States to provide alternative measures if the defendant acted unintentionally and without negligence, [and/or?] if execution of the measures in question would cause him/her disproportionate harm and if pecuniary compensation to the injured party appears reasonably satisfactory.
If there is to be any following of EBay here, then you need a case where a final injunction is going to be DISPROPORTIONATE and an "innocent" infringer. Our existing compulsory licensing provision preclude a final injunction and must already fall within Article 12, but can other suitable cases that may not fit into those strait jackets? It seems to me that they can. In the discussion later on reference was made to property cases where damages had been awarded in lieu of an injunction notably the Wrotham Park Estate Company Limited v Parkside Homes Limited (1974) case.