Who SEZ two wrongs don't make a right? I've practiced this philosophy throughout my life, and boy it works. It gets people to apologize and stop their bad behavior. But ignoring them outright or not giving them consequences, teaches them it's okay to continue being a bully. It's not about hostility. It's about doing what is necessary to stop mean or abusive behavior. When bullies know you'll fire back, they retreat. You can bet that if the commenter didn't "get back" at her mother, her mother saw this as the green light to continue mistreating her. Had she "gotten back" at her, this surely would have made the mother think twice before going on her next tirade towards her daughter.