[adventured]

Yes, it's extremely common to call jQuery from, for example, Google's googleapis.com domain.

Here's a quick sampling from a random group of top sites:

stackoverflow.com (googleapis.com), kickstarter.com (googleapis.com), cnn.com (their own cdn), businessinsider.com (jquery.com), foxnews.com (their own cdn), nbcnews.com (aspnetcdn.com), espn.com (espncdn.com), tumblr.com (secure.assets.tumblr.com), lastfm.com (googleapis.com), lyricsmode.com (googleapis.com), reference.com (sfdict.com, cdn for ask etc), qz.com (googleapis.com), theverge.com (googleapis.com), ehow.com (googleapis.com), wikia.com (googleapis.com), chacha.com (googleapis.com)

[toble]

Just a passing tinfoil comment... Google has so many fingers in the analytics pie, if you're not being recorded by Adsense or Analytics, then there's always CDN.

No idea if it's all linked up, but it means that using alternative search engines doesn't really matter if you still visit Google-enhanced destinations.

[eps]

Of course it's all linked up, including other freebies such as Google Fonts. Why else would they be offering it for free.

[toble]

If that's the case then maybe it would be better for society if we all started self hosted these sorts of resources. Longer load times, more bandwidth usage but better privacy for the public.

[amalag]

http://cdnjs.com/

[shocks]

If you're not paying for it then you are the product.

[andybak]

Or you're walking into an exchange of value with your eyes fully open.

[eps]

And also dragging every visitor of your website along.