Just to correct Mr Chips on one point - They don't threaten to firebomb the homes, they DO!!
How do I know?? Many years ago my neighbour worked for a company that imported animals, not just experiments, that was a small part of the business, but he imported them all the same.
I remember being woken at 0700 by the police telling us to leave the area as there was a fire bomb under his car. There was too, but it was safely disposed of by the bomb squad. It was set to go off when he turned the ignition on, which would've been when he went to work at around 0800 when the street was usually full of kids on their way to school. Nice people huh?