My friend is a manager at a store and he fired a man for bringing his own stuff to sell in the store, which is prohibited. He also gave a warning letter to the other guy who helped that man selling his stuff.
Later, my friend found out that the guy who got a warning letter threatened him behind his back. That person posted on his Facebook that he wanted batter my friend. (My friend is not his friend on Facebook, but he got the info from one of his staff.)
What my friend should do in this case? Just let it go, or talk to that man?