It's been my experience that if you aren't careful with your words, people may react poorly. Recently, I left feedback for a seller whose item took longer than usual to arrive due to shipping delays uncontrolled by the seller. I left positive feedback for the item, commenting on the item being as decribed and shipped promptly. I wrote that the item arrived eight days after auction close, which is fact and proven through delivery tracking. Unfortunately, the seller must have been having a bad day because I suddenly received a reply to my original feedback that was hostile, ending with the word "Really?" in the feedback reply. Clearly, this can be visible to everyone who reads feedback. Whether you are a buyer or a seller, one should be careful to avoid personal criticism, as it reflects poorly. Unfortunately, the seller in question had a history of other similar remarks as feedback replies on his/her feedback and this will definitely put off potential buyers. Never reply back to anyone who leaves negative personal commentary, as it is immature and completely unprofessional; it's best to leave such things alone rather than escalate them.