Let’s not be taken in by the notion that libertarians who make use of public services are hypocrites. I take it that their objection is not to the existence of the public service, but to the coercive recruitment of themselves and (if we are to be charitable) their fellow citizens to its collective provision. But once they’ve already been coerced into paying their share for some public service to which they object, it seems just mean-spirited to then criticize them for using that service too. It would be (rather exactly) like criticizing an opponent of mandatory auto insurance for filing a claim with his (involuntarily acquired) insurer after getting into a wreck. (The Nozick story is less clear, but I’m not sure that Nozick is obliged to be against rent control — that’s a whole ‘nother argument though.)
Libertarian ideology is often pernicious, but there’s no need to throw around the hypocrite label too.