It looks like that was MDY Industries, LLC v. Blizzard Entertainment, Inc., which relied on MAI Systems Corp. v. Peak Computer, Inc. for the relevant part of the ruling.
The person I was responding to was saying that anytime you viewed copyrighted content with a browser you’d necessarily be committing copyright infringement. I’m not a lawyer but I can imagine that the reasoning there would be slightly different from someone simply viewing a post in a browser as part of the intended use of the site.