Analogy is flawed. By your comparison, shutting down the highways would be like shutting down the internet itself. This is like closing down a wearhouse selling counterfeit goods and child porn.
It's be good if users can get the opportunity to get their (legit) data back, but I can't see that happening any time soon.
No it isn't. Megaupload isn't/wasn't selling pirated works. They were providing a venue in which a bunch of law breaking was occurring and instead of allowing jurisdictions to police their citizenry the FBI decided to close the venue and arrest the owner without due process.
While I am in the process of cheering on this type of behavior... I cannot remember the last time I did not see or hear about the police chasing people around and arresting people in the projects next to my office. Clearly, these public housing projects are a venue for unlawful behavior and the owner (HUD) has not taken affirmative steps to rectify the problem. I will be waiting for the FBI to throw everyone out and arrest the HUD Secretary. They won't even have to extradite him.