Conversion is an intentional tort consisting of "taking with the intent of exercising over the chattel an ownership inconsistent with the real owner's right of possession". Wikipedia

A voluntary act by one person inconsistent with the ownership rights of another Wikipedia Disambiguation

Under the common law, the tort of the taking of someone's personal property with intent to permanently deprive them of it, or damaging property to the extent that the owner is deprived of the utility of that property, thus making the tortfeasor liable for the entire value of the property. Wiktionary