[merreborn]

> Like buttons are partially served by Facebook

Yes, the default configuration has your page include javascript from facebook.net which the browser will request on every page view

https://developers.facebook.com/docs/plugins/like-button

In the case of this the theguardian.com page it looks like they've got a webbug as the last element of the body, which results in a request to https://www.facebook.com/tr?

Having facebook count views of your like button is probably considered a feature to publishers.