I don't necessarily share this view but:
Property is theft!Look I won't argue with you, but the very fact alone that many folks do view things differently from you is hint enough that you can't implement your AnCap as straightforwardly as you'd like to believe, i.e. without force.
I've read that piece of drivel, and well, I think I've made my opinion of it sufficiently clear.
If someone considers Property to be theft, and tries to take my stuff, there will be force used. Defensive force. However, note that the use of that force does not change the nature of the society.
Let's take two societies as examples. One is non-propertarian anarchism, the other is AnCap.
In the non-propertarian society, everyone believes that nothing is owned personally, everything is the property of the community, and all is well. But one person decides to keep his TV for a while, or his car, or what have you. At this point, the rest of the population enforces its will upon him and takes back the stuff. The non-propertarian society has violated its anarchic principles to maintain its non-propertarian principles.
In the AnCap society, everyone believes that their stuff is theirs, and your stuff is yours, and nobody tries to steal, and all is well. But one person decides that property is theft, and divests himself of all property. All is still well, and as long as Mr. non-propertarian doesn't decide to use someone else's stuff without their permission, it remains so. But let's say, for the sake of argument, that he doesn't. He decides that he will use someone's stuff, since they're not using it right now. Well, this person is understandably not pleased, especially since he had to come into their house to get that stuff. The AnCap, in defense of his property, shoots and kills the non-propertarian. The AnCap society did not have to relinquish its anarchic principles to maintain its capitalistic principles, nor its capitalistic principles to maintain its anarchic principles.