You're right that it can be spun in a dangerous way. However, we're talking about sites where 95%+ of people go everyday they connect to Internet: they have a first shot at presenting their case to users, they can do it in a simple and convincing way: "Some lobbyists are pushing the Congress to pass a law called SOPA; this law is so bad that it threatens the survival of Internet as we know it, and many companies dependent on it including ourselves. We're so scared that we're willing to give up one day of business, to let everyone realize what a world without us would be like".

(disclaimer, I'm neither a communicant nor a native speaker; but you get the idea, there's a way to spin the black screen explanation in such a way that it's hard to counter-spin).