I have relatives who were subjected to a marking talk in the past 18 months. Their crime? The husband assumed headship of his family and refused to discuss a personal family situation with elders. Unforgiveable!
Defamation of character can't be proven - because no names are ever mentioned when a "marking" takes place. The congregation is left to figure out who the pariahs being described are.
Elders are all now generally slimy scum-bags, because deep down they know what they're doing is brutal & vicious. "We were only obeying orders" will be their cry.