Oh wow I thought only France has squatting problem. here the squatters can legally occupy your place for 48 hours, and if that's your only place and you went away on vacation tough luck buddy, they can shit on the floor and tear the walls down Good luck getting your money/property back
2) Now the law changed and it is much easier and faster to kick them out. It was always illegal to squat, now sanction are higher
3) Most squatters are not targeting houses. And all the time squats are mainly building not used for years (as it safer and easier for squatters, and sometimes as a way to "minimize" disturbances)
Please note that in Holland some kind of squat were legals for years (only for building not used for years and with obligation to not damage the property and to give it back quickly). Seems interesting to me