lbrandy has it right here. If your definition of "tracking" is "web server log analysis," then nearly every web site you visit is tracking you.

It's really nothing to worry about though, unless Facebook is doing something to de-anonymize that (otherwise stateless) data. They could probably do that (by noting the IP and User-agent seen when logging out, for example), but they explicitly claim not to in a number of places, most recently by lbrandy in this thread.