Specht v. Netscape
A 2002 US case holding that license terms tucked below the download button don't bind whoever clicks it.
Netscape's SmartDownload plug-in was fetched with a single click on a button. The license terms, arbitration clause included, sat further down the page and were visible only to those who scrolled. When users sued because the software had reported what they were downloading, Netscape tried to force the case into arbitration under those very terms.
The Second Circuit, in an opinion by Sonia Sotomayor, refused. A reasonable user had no reason to suspect there were any terms at all, and clicking "Download" agreed to nothing. The ruling drew the line between clickwrap, where you actively accept, and browsewrap, where the terms merely exist somewhere on the site. Ever since, the terms have gone above the button rather than beneath it.