In any case, it doesn't seem that Sony nor the MPAA (which is mentioned in the article but didn't apparently contact the county at all) asked for the network to be shut down. Further, there's no legal basis on which to close down a network because of illegal use. The common-carrier and other ISP laws protect such operations, even though if Sony had filed suit the ISP might have had to produce certain logs and other connection records.
My friend Cory Doctorow over at BoingBoing went with the knee-jerk headline: "MPAA Shuts Down Entire Town's Muni WiFi over a Single Download," when it wasn't a whole town, the MPAA wasn't apparently involved, and the shutdown was by the county, which didn't have to do so. The MPAA told MediaPost that it "didn't ask for the network to be shuttered."
What's likely here is that the county overreacted, and decided to limit any potential liability immediately, even though no sanctions or actions were apparently threatened by Sony (or the MPAA). In similar cases, private and governmental bodies have simply said, "Whatever" or turned to groups like the EFF for support.
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