In part, he said the recording industry had not presented evidence linking the alleged file swapping to the ISP subscribers that was strong enough to warrant breaking through critical privacy protections.
But he also questioned whether CRIA had a copyright case at all.
With respect to downloading, the judge accepted the Copyright Board's early decision almost without comment. But he went further, citing a recent Supreme Court decision to say that making music available online also appeared to be legal.
In that recent case, the Supreme Court ruled that libraries were not "authorizing" copyright infringement simply by putting photocopy machines near books. The libraries were justified in assuming that their customers were using the copiers in a legal manner, the high court ruled.
Finckenstein said the same rationale should apply to peer-to-peer users.
"The mere fact of placing a copy on a shared directory in a computer where that copy can be accessed via a P2P service does not amount to distribution," Finckenstein wrote. "Before it constitutes distribution, there must be a positive act by the owner of the shared directory, such as sending out the copies or advertising that they are available for copying."
Ottawa's Geist said this appeared to make uploading itself legal as well, since a peer-to-peer user--like a library--would be entitled to assume that the person on the other side of the connection was acting legally, since downloading was also legal in Canada.