This happens just about anywhere in the world, and the greatest perpetrators are friends and relatives. The FBI even has a webpage for it: House Stealing
This happens all around the world. Not just in underdeveloped countries.
I agree this happens every day even in the so called first world countries...
the notary thing... on paper it looks good and it gives you rights... but some people just won't care and do stupid things betting on the slow justice times.
I've seen some of it, luckily not directly.
Justice can be very very slow in these cases and you'll have to pay lawyers for years.
Usually people get pissed off... things gets stuck for years... then random "accidents" happen. Like fire, explosions etc and there we go. Land is clean again
and get this: You can get arrested and RUIN your life if you try to evict the squatters WITHOUT going through the "HIGH PRIEST," aka. the courts after handing "officers of the courts," aka. lawyers hundreds of thousands of dollars (maybe even millions***) in legal fees... a TAXABLE EVENT!
PS. Having gone through the US legal system personally and as a Pro Se defendant, I can tell you it's almost impossible to fight the Leviathan without LOTS of BRAINS, BRAWN, and BIG BUCK$$$$$$$$$ of unseizable money!