The court, on the contract issue, found that people would not expect to find an arbitration restriction in the warranty brochure, and without something else pointing them at it, it wasn't good enough.

"Here, Samsung entitled the brochure “Product Safety & Warranty Information.” The title would not put a reasonable person on notice that the brochure contained “a freestanding obligation outside the scope of the warranty.” "

The court would have been satisfied if they had put a big ole sticker on the phone screen that said "the warranty brochure contains important arbitration restrictions, you should read it".

No active acceptance necessary ;)

The court was also clear that in-box unilateral contracts are okay under california law.

In this case, you are right the question will be whether someone would be expected to notice it exists.

Unlike a random warranty brochure containing arbitration provisions, EULA.txt and friends are common in software, so a court is likely to find the terms would be there. Of course, if they lose they'll clickwrap it and win.

Don't get me wrong, i think in-box contracts are nonsense, but my personal view is not the law, or even close to it.