Possession 285

mortgaging them), you cannot sue a third party wrongdoer in conversion, but your bailee or mortgagee can do so. Your bailee or mortgagee will, however, be liable in conversion to you if they do anything in breach of or outside the terms of the bailment or mortgage which gives you an immediate right to the return of the goods and which is adverse to your possessory rights (for example, by wrongfully selling or refusing to return the goods).

Remedies

It will be apparent from the above that the tort of conversion has the potential for over-compensating the claimant and unfairly penalising the defendant. As Weir points out in Extract 7.2 below, there is a problem about multiplicity of defendants since the events causing the loss of the claimant’s goods may have involved a series of conversions by different people, each of whom is prima facie liable to compensate the claimant for the full value of the lost goods. This is so even if the claimant is only a bailee, with a limited interest in the goods. Also, in assessing damages, the conduct of the defendant is irrelevant (the liability of the thief who steals the goods is the same as that of the innocent purchaser who buys the stolen goods from him), as is the amount (if any) of the defendant’s gain. All these problems were considered by the Law Reform Committee’s

Eighteenth Report on Conversion and Detinue (Cmnd 4774, 1971) and as a result substantial changes in the law were made by the Torts (Interference with Goods) Act 1977.

Trespass

What amounts to trespass

Both trespass to goods and trespass to land involve an unlawful direct physical interference with someone else’s possession. No damage to the land or goods is necessary – any direct physical interference is actionable. Unlike conversion, trespass is not a strict liability tort: the interference must probably be intentional or negligent. There is a defence of necessity to an action in trespass (for example, that the defendant was acting in the public interest to avert danger) but it is of very limited scope, and has been held not to justify homeless people taking over vacant local authority housing (Southwark London Borough Council v. Williams [1971] 1 Ch 734, CA) nor protesters against GM food digging up GM crops (Monsanto v. Tilly [2000] Env LR 313, CA).

Who can sue

Trespass is an injury to possession, and the only claimant is the person who was actually in possession of the land or goods at the time of the trespass (although see Palmer, Bailment, pp. 204–6, for some exceptional cases when a bailor can also sue and also Monsanto v. Tilly [2000] Env LR 313, CA). The claimant need not also be the owner – in the case of goods, finders, and even thieves, can sue