…due to pending legal action by the RIAA?

If the judge rules that we’re each legally responsible for all of the traffic that comes through our ISP account, open, unprotected Wi-Fi hotspots would become a serious legal liability, the hundreds of thousands (millions?) of people who depend on their neighbors for Wi-Fi will be out of luck, while altruistic (or ignorant) folks who leave their wireless networks open could find themselves embroiled in an RIAA lawsuits even if they’ve never shared a single song in their lives.

Wired.com blog post