Whether or not you actually click on them, you are "using" them. Last I checked (admittedly, a couple of years ago), if you've used that browser to log into facebook and haven't cleared your cookies (or configured / installed a privacy add-ons), facebook is able to associate that page view with your account through the like button on that page. They bypass the 3rd party cookie mechanisms that are suppose to be in place to prevent this.

If anybody knows if this is has changed, please chime in. I'd love to know.

edit: whoops, looks like somebody made the same comment before me, so i assume its still something they do: https://news.ycombinator.com/item?id=5369214