Just to chime in with some relevant Canadian case law... In the case of Voltage Pictures VS TekSavvy Solutions Inc (an independent Canadian ISP), it was argued and ruled that an IP address alone is insufficient information with which to make a legal claim for three main reasons.
An IP address alone may identify the subscriber of the service used, however it does not prove who the physical end-user of the device used actually was.
An IP address alone does not prove that the contents were downloaded in their entirety, or that they were shared with anyone else.
An IP address alone does not verify the device that was being used to commit the act.
Given that these have been accepted as being reasonable objections, it is likely that in any common law country, that the courts would take the same stand.
