What makes you think you have to be a pirate to be against SOPA? I spend $60+/mo. downloading movies from the iTunes store, to keep on the right side of the law. I'm still 100% against censorship, and especially censorship that serves no legitimate purpose.
And on a personal note, I think your response is even more generalizing and patronizing than the pirate's post. I'd sooner have a beer with him and try to convince him why he's wrong, than have to sit at a table with you for an hour.