"Another U.S. judge has ruled that an IP address does not identify copyright infringers, as the person paying for Internet access might not be the individual downloading illegally obtained content. The decision is one of many over the last year that are thwarting the plans of copyright holders who are looking for piracy-related financial gain in the American court system.
This particular case is unique because the judge actually goes into detail as to why content owners can't go after individuals using an IP address. The ruling was filed by Judge Gary Brown in the United States District Court of the Eastern District of New York in response to numerous lawsuits filed against John Does by adult film studios."
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