Law schools students learn in their first year Property class about a thing called "adverse possession". Adverse possession goes way back. It basically means that if you openly live somewhere long enough, and nobody objects, it's yours. Legally. The statute of limitations varies from state to state: I believe in North Carolina it is seven years. So if I squatted in an empty house for seven years, and made no secret of it (i.e., I didn't "hide"), then after seven years, the house is mine.
Texas adverse possession law is a little trickier, and a little better for potential adverse possessors. One guy did a little research, got a little clever, and now he's got a fairly decent legal claim on a $330,000 house that he's been squatting in for three years.