לישועת אלחנן בן הענא מרים
Hilchos Lashon Hara chapter 10, section 11
A person must be very careful not to tell others that he did business with so and so and was cheated, robbed, shamed, distressed by him and the like, even if one knows that the story is true (except in the case explained later in paragraph 13) even if the leniencies above apply. Because in such a case one's intent is certainly not for beneficial reasons so that people should disparage evil doers and keep from their evil ways, or that the person might leave his evil when people disparage him. Rather, one's intent into is to disparage him because of what he did and the more shamed he is by people the more one likes it.
Hilchos Lashon Hara chapter 10, section 12
This applies even more if the person did not harm a person but only failed to provide some benefit he should have, such as a loan, charity, or hospitality. If one reveals this in order to disparage him it is absolute lashon hara as we wrote above (5:1). One also transgresses other negative commands as explained there. Many people stumble in this matter. If they are not well received in a town, they disparage the important people there for not helping them. This is even worse if he disparages the whole town and a terrible sin. For lashon hara applies when speaking about an individual and even when speaking of a whole Torah observant town.
[PS - Why do people name their kids "Rob"?]
