People who pay a fraction of retail for a used item and expect a piece better than new.
Sold a used subwoofer to an anal customer at close to one third of the retail price with clearly stated, conservatively rated 8/10 condition. After receiving it, he puts it under fluorescent lights looking for wood imperfections. Then proceeds to accuse me of obfuscating the truth, poor packing (double-boxed) and every other imaginable audiophile sin that exists on the face of the earth. Lesson: never ignore the red flags dealing with a bloody anal type.