>Or they've ad-blocked the ga.js.

That's what I've been doing. I've simply been using AdBlock Plus to prevent anything from Google Analytics from loading. I found that Google Analytics would often take the longest of any element to load, causing my browser's progress bar to spin indefinitely instead of finishing the page. Blocking Analytics entirely got around this annoyance.

In any case, it's nice of Google to provide this to the privacy-conscious.