I agree with non aggression. The fact that people think they have a right to strip me of my production because they can't physically touch it and can't recognize aggression when it's in their face is beyond me though.
I again recommend reading the paper (it's only 73 pages and HIGHLY footnoted, so it's really more like 30-40 without footnotes), especially the sections titled "Some Problems with Natural Rights" and the next titled "Property and Scarcity". Kinsella argues (and I agree), that the need for property rights with tangible goods arises from their scarcity. My use of some object necessarily denies you the use of it. To solve this problem, we label one person the "owner" and in order to use the object, the owner must consent. There is no such scarcity in the realm of ideas, many people can use the same idea at the same time, thus property rights do not make sense.