On a global scale; most Postal Authorites are national monopolies. For example:
In Canada, legislated examples include:
Policy examples include:
As you might have gathered, most high tech infrastructure companies that existed before the 1990's were somehow related to a GovernmentSanctionedMonopoly.
That's not exactly true. It depends on what you consider property, I suppose, but I don't think many people would disagree that you own something if you can prevent others from taking it, particularly by physical force. Before copyright, patents, and trademarks, ideas were protected as property by keeping them secret. This was less useful to society than publishing them, so the government opted to legally protect an published idea proviso certain legal restrictions. This creates a GovernmentSanctionedMonopoly of published intellectual property, but certainly the government also sanctions companies to keep trade secrets as the company sees fit; otherwise companies would be required to publish all their information. The drawback, of course, is that while trade secrets are government sanctioned (i.e. they are legal), they aren't protected as monopolies. If someone else copyrights, patents, or trademarks your idea first, you lose.
Of course, the full story would be that copyrights aren't even monopolies because the typical legislation allows that a third party, acting fully independently as you (i.e. in complete ignorance of your work), may recreate your work and also claim a copyright. FairUse also dilutes the monopoly. On another point, trademarks are only tentatively protected by the government. If the trademark holder fails to enforce the trademark (in a government court of law), she will lose it. This makes trademarks unlike either copyrights or patents in that copyrights and patents are somewhat automatic, even if governments won't prosecute on your behalf.