Trespass to chattels is defined as intentional interference with the lawful possession of a chattel in the United States. This can be pretty much any kind of physical interference, such as taking, destroying, or restricting access. There must be damage in order to recover. Legal Definition of Trespass to Chattels
When a person converts property for their own use, this is known as conversion. It is essentially a form of theft. If you find someone else’s property and keep it, you have likely committed the tort of conversion in addition to committing a crime. Do you know how people are always asking where they can find and keep the money? This is called a conversion. Conversion can also occur if you give the impression that the property is yours. The property owner has the right to sue for the loss of the property; even if the person recovers the property, they can sue for loss of use for the period in question.
Conversion occurs when one person takes another’s tangible personal property on purpose.
Trespass occurs when one person intentionally interferes with another’s right of possession of tangible personal property without taking it away. This usually entails physically damaging the property, but the damage is not always required.
So one is interference, and the other, even if temporary, is theft. This is, of course, common law. Each jurisdiction’s statutory law must be examined, and different countries have different requirements.
Can trespass to chattel be an unintentional act?
Trespass to chattel varies by jurisdiction, country, and so on, but it usually includes an intentional act. The most notable exception has been the broadening of the tort approach to electronic and digital trespass. Given that legislative bodies are usually years behind the trend in torts, I believe it will be the traditional expansion based on common law standards and precedent. The article mentioned in an earlier answer has a good discussion of trespass in this area.