I'm not a lawyer by any strech of the imagination, but isn't a penis pump a medical device? I think the free speech issue would override any question of obscenity. I don't think anybody--even Betty-- could be titillated by the sight of a giant replica of Mel's Swedish penis pump. Granted, the mainstream media may not show pictures of a giant penis pump, but a lot of internet media would (Daily Rotten, FARK, Something Awful, to name a few) and draw attention to the issue. Something like a giant penis pump at a protest would be too damn weird for them not to post--that's what those media outlets do, and they reach a hell of a lot more people than you may think.