I've heard stories about squatters and how the supposedly have rights to claim a domicile as theirs when a family is away for some extended length of time. This would be almost impossible to happen where I live because so many people know who lives where and what is going on in our neighborhood. That and the fact that the local police drive through numerous times each day and also know the residents by name.
Now, let's say someone did come home from an extended trip and found squatters in their home. What are his options? How about breaking in, since you can't really break in to your own home, and forcing them out at gunpoint? How about cutting off the water at your in-ground meter head in your yard? How about calling the electric service utility and having the power turned off? How about waiting until night and then shooting them since they would fall under the label of burglars?
Few things would infuriate me more than to have something like this happen to me.