They have them in some of the lakes and rivers around Washington. I've seen Asians keeping them, but most everyone else just throws them away or buries them for fertilizer. They are considered a trash fish and they're one of the few fish that it's legal to fish for in WA without a fishing license. It's legal to take them in any way that doesn't involve firearms, explosives, poison, or electricity, so people can spear, net, or bowfish for them. It used to be illegal to return a carp to the water, though I'm not sure if that's still the case.
Don't worry, catch crappie.