Well I'm against DC shutting down to protest SOPA/PIPA. It doesn't make sense to me and I don't see how it helps the cause.
In protest of this, I won't be visiting DC on Jan 18!
While it may not really make much sense to shut down DC (in that one small act), I think it's a good thing for sites like Wikipedia to shut down and show people what SOPA and PIPA and PROTECT IP and that other draconian one whose name I forget, will give them.
Shutting down DC in protest is a good sign of solidarity.
I think all of us here "get it" and understand that censorship is bad, and free speech is good -- but that's not the point.
I think mouser would have to say exactly what his motivations are, but as I see it, it looks like a show of solidarity.
Think about it this way, if one person were to protest, oh, say plastic bottles by throwing 1 plastic bottle on the steps of city hall, it would be pretty meaningless. Get 10,000 people to do it, and you have a statement.
If we all add our 1 grain of sand to the pile, we'll build a mountain.