Some activists have attempted blackmail and other illegal activities, such as the intimidation campaign to close Darley Oaks farm, which involved hate mail, malicious phonecalls, bomb threats, arson attacks and property destruction, climaxing in the theft of the corpse of Gladys Hammond, the owners' mother-in-law, from a Staffordshire grave. Over a thousand ALF attacks in one year in the UK alone caused £2.6M of damage to property, prompting some experts to state that animal rights now tops the list of causes that prompt violence in the UK.