Getting around the paywall by turning off cookies- how do we stop that?

We recently discovered that you can get around the TownNews paywall on our site by simply disabling cookies. I have also tested this on other TownNews sites and found that to work there as well. Is there any way we can set up the paywall so that if cookies are blocked, the user automatically has to sign in if they aren't already? Or some other deterrent that if the user disables the cookies that they aren't reading our site for free?