> Many sites have Facebook share buttons that don’t actually load anything from Facebook unless you use them - they use a locally hosted button
This is incorrect. "When you load up your site with a host of sharing buttons you're – unwittingly perhaps – enabling those companies to track your visitors, whether they use the buttons and their accompanying social networks or not" [1].
> the Facebook pixel, a common target of the scorn of privacy advocates, is only in use on ~12% of the top 1 million sites
So only tens of millions of people whose browsing history is being siphoned off without their consent?
This is incorrect. "When you load up your site with a host of sharing buttons you're – unwittingly perhaps – enabling those companies to track your visitors, whether they use the buttons and their accompanying social networks or not" [1].
> the Facebook pixel, a common target of the scorn of privacy advocates, is only in use on ~12% of the top 1 million sites
So only tens of millions of people whose browsing history is being siphoned off without their consent?
[1] https://www.wired.com/2013/03/social-sharing-buttons-that-re...