There is a very small rumor that they might post signs at the cemetery stating that entry is not allowed. Until such an event, it would still be legal to enter the grounds. Posting signs, however, would still present a challenge on their part and would certainly not be in the best interest of the public not to mention the cemetery.... As history has shown, trying to prevent entry to the cemetery and limit "foot traffic" only isolates the area and becomes more prone to vandalism.
If a sign does become posted I would certainly challenge the issue and try to have it removed. That is of course, unless the vandals remove it themselves on a constant basis.... Yet another challenge I suppose, and if a sign is not present upon arrival a visitor would have no idea they are not to enter, hence they can't be issued a fine let alone be arrested on their "first" recorded warning. But I would still focus my resources on having it removed anyway and present to them the very positive effects of keeping it open to the public.
Pete