Which finally brings us to the nub: you don't know what freedom is, so of course you can't regret losing it--or even know whether it's been lost. Ther's no such thing as "un-free by choice". "Freedom" is the power to choose. If you enter into a voluntary contract, you are under obligation--but you are perfectly free. If on the other hand I hold a gun to your head and force you to enter into a contract, then I have taken away some of your freedom.
Ironically, I believe in security measures, possibly including random searches, as long as they are voluntary. In the case of the subway, that means that the subway must be privatized. As private property, the owner can set conditions upon entrace, and the consumer can decide whether to accept those conditions or take his business elsewhere. If the subway owner makes bad decisions, his business will collapse, and he will be bought out.
When the government makes bad decisions, the business can't collapse: they will merely expropriate more funds from unwilling "donors" and continue funding it.
I have to work. Fine, I don't share your definition of freedom. Conversely, you don't share my priorities. I happen to live in a place where there is more latitude to do as I please and more opportunity than almost any place else on the planet -- and we remain a target of some very bad people. I, for one, appreciate and admire the guys who work to keep us safe.