Browser extension that prevents Google search from tracking clicks
Every external link on the search results page has a mousedown event callback.
The callback rewrites the href attribute to a Google-internal link.
A click on an external link is thus instead redirected through Google without
the user's knowledge.
Other privacy-related extensions might already mitigate this problem. I haven't done extensive testing, but it seems that ublock origin already fixes this behaviour.
To see if you are still affected, just search anything on Google and right-click on one of the results. If the url of the link changes to a Google-internal link, you can be tracked.
The extension adds an event listener for mouse events (and some others) that
stops the propagation of the event. The Google code that rewrites the
href attribute is never called and the original href attribute is preserved.
Clicking on a link therefore brings up the result directly without going through
Google.
See the list of configured domain matches of this extension. The list of domains is taken from https://www.google.com/supported_domains. If you find another Google search domain, please let me know.
This gist gave me the idea of stopping propagation of events to solve this problem.