Actually, I spoke too soon. This is a legally-permitted billboard in an Industrial zoning district. My mistake...

Thanks for looking into the sign. Is there anything we can do about it?

Billboards are legal only in industrial zoning districts throughout the City, with specific spacing requirements. This one happens to meet all the requirements, which is rare. Aside from changing the ordinance, which has been challenged and upheld by the Supreme Court of the US (which means the City Attorney will probably argue to keep it the way it is), there is nothing really to do about this one.