I believe it will help the forum in general, is is a very positive move for such rule, nobody deserves to get scammed from such tactics, it will also make this place safer to conduct business for even somebody who is not familiar but want to start something this rule will help him see more clear what is going on and not rip him out, sell or re-sell illegal (morally talking) stuff that are other people's work.
100% agreed on adding such rules.
Transparency is everything.