I'll grant the technicality.
But you must agree that one can take land they never had title to. (To use a preposition to end a sentence with.)
Anyone who can hold and defend the land from all comers owns it.
If that's the case we have already surrendered to Mexico and they own us.
” Anyone who can hold and defend the land from all comers owns it. ”
That is the definition of ownership of everything - you only own that which you are willing and able to defend, by whatever means at your disposal.
Most of us use the power of the state (police) and the rule of law to defend what we own. But what happens when the rule of law no longer works as it happened in Ferguson?