This is specific to France (and maybe other countries, but I doubt that there is any other with such a surrealistic legislation like ours)
In France, when someone breaks in to your house and stays there for more than 48 hours, the house becomes their permanent residence and you need to go though hoops to have them evicted (and god forbids if there are children or otherwise protected populations among the squatters). EDIT: the 48 hours always apply when you do not live in the house, and is often applied by the police forces in other cases (see the second link below)
Relevant information (in French):
a lawyer article summarizing the current (post 2018) state of the law:
a Le Figaro article which discusses the 48 hours delay:
A comment on another question where I brought this up asked whether me breaking into my own house and changing the locks makes me a squatter too. Can the squatters sue me for removing them the possibility to get back into "their" house?
I am interested in the scenario above, not one where you come in by force and throw them away. This is not a good idea, legally speaking, and all the articles about squatters specifically advise you against this.