It's worth pointing out that "sudo is up to you". So leave /usr/local alone if you like. Or install Homebrew to ~/homebrew. Whatever you choose. Homebrew was designed to be flexible and non-intrusive.<p>However the suggested step is suggested because:<p>1. On OS X /usr/local isn't even there on a fresh install, so nothing that should run as root is there by default.<p>2. Mostly people use Homebrew to install a few tools that are missing, these tools don't need to run <i>as root</i>, so they are as vulnerable as TextMate is (because you dragged it from the DMG to /Applications and it installed as your user).<p>Now you can argue that you should thus install to ~. And you can of course. However I've found over the last eight months that a great deal of build systems have bugs and don't find dependencies if you install the deps outside of /usr or /usr/local. So for a trouble free life we suggest /usr/local.<p>Finally sudo is dangerous. You should only use it with tools you trust. Do you really trust a half baked Makefile made by a developer who doesn't really know how to write Makefiles?<p>All in all I think depriviledging /usr/local is safe and the least hassle for Homebrew on OS X.