This is not true. Your first and second house are protected by the law. If someone enters in your first or second house when you are outside, they will get expelled in the same moment the police arrives, and they will face criminal consecuences.

The problem comes when you have 200 houses and somebody squats one of those where you don't live and you don't use. A problem for the banks, vulture funds and big renters. And to be honest, I cannot care less..