> He did not rent the place out, but preferred to keep it to themselves as a pleasant place to spend a few weeks to months as they are getting old now. But after this incident he sold it quickly.

If it's their primary residence, then it's not considered "occupation" but rather "breaking and entering", and contacting the local police would get the criminals removed quickly, without much fuss.

It sounds more like it was a vacation house, and potentially for people who don't actually live in the country. In that case, it gets harder to claim they're in a morally superior position, especially considering the housing crisis we face here, that gets worse and worse every day.