Itch.io allowing the sale of stolen or pirated games.
Evidence indicates that there is no (or very lax) verification on itch.io to confirm that the person selling the product is actually the owner.
This copy of RimWorld that was found on the site turned out to be pirated copy.
It is obvious that more work has to be done on the verification of the product being sold.
If Itch.io had actually looked at the contents of this RimWorld sale it would have been quite obvious it was not the legitimate developer.
All of the game store pages shown below have since been removed from Itch.io.
Undertale and Stardew Valley below were both being sold by the same person - ‘Cheap Games’.
Whoever was selling the pirated version of RimWorld was using the correct developers name and the storefront does look legitimate.