Read the whole thing, but the last few points help to explain why the push for SOPA is coming right now:
7. Modern communications technologies (including the internet) provide people with a limitless channel for self-expression (not to mention distraction — endless circuses without the bread). They also provide the police state with a limitless flow of intelligence about the people. Note also that it’s possible to not merely listen in on mobile phone calls, but to use a mobile phone as a GPS-aware bugging device, and (with a bit more smarts) to have it report on physical proximity (within bluetooth range — about 20 feet) to other suspects. The flip side of social networking is that the police state knows all your acquaintances.
8. So I infer that the purpose of SOPA is to close the loop, and allow the oligarchy to shut down hostile coordinating sites as and when the anticipated revolution kicks off. Piracy/copyright is a distraction — those folks pointing to similarities to Iranian/Chinese net censorship regimes are correct, but they’re not focussing on the real implication (which is a ham-fisted desire to be able to shut down large chunks of the internet at will, if and when it becomes expedient to do so).