While you arbitrarily rule out “pet ownership” from your hypothetical, this is a reality for people who live with bully-breed dogs (pit bull types and their relatives). Some jurisdictions ban them, some have taken them from their families by force, and some have reversed bans after second thoughts (and evidence of the ineffectiveness of breed bans) piled up.
It shouldn’t be surprising that “underground railroad”-type organizations have sprung up to move dogs of banned breeds to safety.
Legislators have responded by writing BSL (breed-specific legislation) that explicitly forbids veterinary opinions from being used to define a dog’s breed – because the legislators suspect vets will say whatever’s necessary to protect the dogs. In other words, the legislators anticipate civil resistance to their law (but somehow still assume it’s a good idea).
Defiance of the government to protect nonhuman family members extends beyond dogs, of course. Despite repeated warnings not to bring animals along on hurricane evacuations, enough people have started to refuse evacuation – or bring them anyway – that law and gov’t policy have been changing.
Years ago, an outbreak of some disease in California caused factory farms to worry about their investment in birds, so the legislature considered a bill requiring the agriculture department to kill large numbers of chickens and other fowl to prevent the spread. The order included birds kept as pets, like parrots and pigeons, and included strict quarantine rules – no birds were to leave the infected zones or the state.
I was active on a lot of parrot message boards and online sites at the time (living with parrots myself, although on the East coast) and I can tell you that large numbers of people smuggled their parrots out of California immediately in a sort or “underground railroad.” Large numbers of people either transported birds out of the quarantine zone, prepared to do so, or cooperated.
As it happened, the “we’re coming to kill your family members” part of the bill never was put into effect, but the mere word of being considered it immediately invalidated the quarantine, as birds were moved out of the zone without medical supervision.
People are generally pretty serious about the government banning or killing their family members.
Apparently this is an issue that continues to be in the news.