I'm guessing that they are actually talking about the information gathered when loading the FB objects that are located on FB's servers. There is quite a lot of information you can collect whether the button is clicked or not. See web bugs http://en.wikipedia.org/wiki/Web_bug look at the "On web pages" section.
On the other hand this behavior is one of the reasons I use 'ad blocking' and no-script plugins. Part for the annoying ads but also to stop 3rd party tracking.
It's not that FB is tracking every click but they can piece together the sites you visit that have a like button. No click required.
Is there anyway to get a list of doctors in my area that are using this service. I would really like to only use these doctors from now on. I like the fact that they do not have to spend so much time and mental energy worrying about negative reviews and can instead focus on providing me with excellent care.