Nope there not illegal. Flirt and spring poles are not paraphernalia they are actually great tools used for both play and conditioning dogs for show. I'm in Northern CA but I've been harassed many times by my neighbors and AC, for my spring and flirt poles. AC comes out and see's what nice playful dogs I have and they walk away laughing.
If peta or the hsus has anything to say about it... Treadmills, Break sticks, Breeding Stands, Chains, Flirt Poles, ect are all forms of DF paraphernalia. None of these things are in fact DF paraphernalia though. They are all when used properly perfectly humane and not against the law( At least not yet). Although if law enforcement ever showed up at your house with any of these things and a pitbull in the home you bet your bottom dollars they would assume you were fighting your dogs. It's very sad the ignorance that surrounds our breed.
i live in nc and i have a homeade spring pole hanging from my tree. harness, weights flirtpoles and my dogs are always swinging on the rope and walking around my house pulling weights and climbing up trees, its like a huge jungle gym, im sure my neighbors think im crazy.. so does my wife..