See http://en.wikipedia.org/wiki/I_Love_New_York for one famous example.
So, while you are right about the ability of a gov to register and/or patent things, I'm surprised they'd be willing to follow through. It's not as though Apple is trying to make money off of them by selling a knock off product or piggybacking on an advert campaign.
Good point none the less and thanks for the explanation.
It's not about money being made, it's a legal necessity that a trademark owner needs to actively defend the mark in order to keep it.
Sometimes the claims of infringement are upheld, sometimes not. The more important thing, legally, is that NY needs to show that they are actively defending the mark to prevent trademark dilution.