Well, Libertarianism usually means very little government and as a consequence, very few laws. So there is no need to have elaborate mechanisms to "consent" to

Well, Libertarianism usually means very little government and as a consequence, very few laws. So there is no need to have elaborate mechanisms to "consent" to countless laws. Though the precise amount of "laws" varies depending on which Libertarian you speak to. They will all, however, agree on property/ownership law and the Non-aggression principle. It's actually quite elegant, because you could define all sorts of "laws" or prescribed/prohibited behaviors simply by following through with the consequences of the above principles. E.g. Fraud, or breaking a contract. The money and ownership of goods was transferred from one entity to another. If one side "refuses" to hold up their side of the trade, then they're effectively depriving the other party of the use of the property that they own.