In Germany, where I'm from, it is against the law to declaw a cat. Declawing is considered cruelty to animals, and is therefor forbidden. The reason indoor cats claw furniture is, because it is against their nature to be permanently indoors, and they are miserable because of it. I have had cats all my life, and currently have two, who are 5 and 9 years old. They have a cat door and come and go as they please. They have never, in all their time with us, clawed at anything in our home, and neither have any other cats we've had.
That said, I would be livid, if that had happened to one of my pets, and I would seek retribution (even though obviousely you can't get your poor cat's claws back). I have never in my life sued anyone, but would possibly consider it in this case.