If user knows what this mods looking for, he can avoid it. And that can be done very easily. As you probably know, cookies are easily controlled within any browser, just deleting all cookies, or if user is more technically inclined, deleting only cookies associated with site in question, disables this mod from knowing this user.
Usually the most annoying users learn this fact fast.
If someone would implement something like
http://samy.pl/evercookie/ this would make deleting cookies harder, but not impossible.