What am i missing here?

Ray Gronberg, in Wednesday's Herald Sun:

Planners and elected officials may have little control over the timing of the debate once a Georgia billboard company decides it's ready to press for a revision of Durham's restrictions on its business.

Fairway Outdoor Advertising, is taking advantage of a provision in local law that allows anyone to ask for a change in development rules, City/County Planning Director Steve Medlin said Tuesday.

For a fee, the company has the right to a hearing with the City Council and the County Commissioners, Medlin told a joint panel of both those boards.

Medlin said his staff is busy researching billboard issues because he expects debate to unfold quickly once Fairway settles on a proposal.

"They're not going to go away," he said, explaining why he's having his subordinates do background work. "When it comes, it's going to come quick and it's going to come hard. I don't want to be unprepared."

Fairway officials want the right to replace some existing billboards with electronic models that can flash different messages every few seconds.

The company also wants permission to move and upgrade some billboards, City Council member Diane Catotti said.

State officials have told planners there are 89 billboards in the city, down from 101 at the start of the decade, said Julia Mullen, a planner in Medlin's department. Fairway is said to own 54 of them.

The city and county don't allow new billboards but a federal law bars them from ordering the removal of those that do exist.

Vicki Jean DeHamer, in the Cary News last week:

A decision the Town of Cary made more than 20 years ago to eliminate all large signs and billboards is still being argued in court.

The Cary News last reported on the issue in March 2008, highlighting a Fairway Outdoor Advertising billboard that has stood on East Chatham Street for over 50 years, which town officials decided was overdue for teardown.

The town approved a Land Development Amendment in 2003, putting all rogue signs on notice and officially starting a three-year countdown for removal by July 1, 2006.

Two holdouts emerged: Fairway’s billboard and South Hills Mall, for a sign on the side of I-440 North that’s too tall.

The deadline came and went, and both Fairway and South Hills’ owners left their signs standing. Fines started to rack up, eventually to the hefty rate of $500 a day.

An appeal by Fairway in March 2008 was denied by the town’s Zoning Review Board. South Hills did not respond, according to town officials.

The Fairway billboard stands to this day, some calling it “the last billboard in Cary.”

Last i checked, Cary and Durham were both still in the United States. Why does federal law prohibit Durham from ordering the removal of billboards, but not Cary? What am i missing here?