The Internet's growth enables consumers to critique brands openly, but these criticisms may be deemed unsubstantiated by others who label these consumers as "Karen," signifying them as problematic. Occasionally, consumers may voluntarily defend the brand. These critiques and defenses, part of online reviews, significantly shape the brand's eWOM. Despite the widespread use of the term "Karen" for problematic consumers, prior research did not clearly show how "Karen" triggers consumer online brand defending. Our case study on Costco Taiwan indicates that consumer actions prompting online brand defending can be categorized into three groups: (1) Disruption, (2) Critics, and (3) Abuse. Further details on these behaviors and potential responses are provided.