I’d have to go digging, sorry I don’t have the time right now. It was to do with piracy on the OG X-Box. It wasn’t the main part of the case, just a tangential point inside the judge’s ruling.

Downloading a game to play it would be copyright infringement. Downloading involves making a copy on your device. However one copy really isn’t worth the hassle of claiming against, so it never happens. This is why all the Napster cases inflated the counts of infringement by including everyone you connected to as if you had uploaded a complete copy to them, that’s the only way to make the claim worthwhile. Also in the US uploading to someone carried punitive damages, similar cases didn’t work so well in the UK with actual damages.

Downloading it to study is fair use under the research exemption, particularly if it’s a non-commercial activity.

Copyright infringement happens all the time, but the vast majority of cases aren’t worth prosecuting, and there’s no penalty for a rights holder not to prosecute. Meanwhile, with Trademarks, the rights holder absolutely can lose their rights if they don’t prosecute every infringement they become aware of.