What is even more worrying for me, and the way I understand SOPA (note that my understand comes exclusively from reading the news, mostly Hacker News, I haven't read the law), is the fact that copyright holders can cause a website to be "banned" from the internet (i.e. domain unresolvable, deleted from Google, funding cut) without any proof. So, in this case, the whole congressman's website could be "put offline", and fair use/willful infringement wouldn't even matter - unless, later, the congressman would decide to challenge the action in a court of law.