You posted that this person had sold all of their

You posted that this person had sold all of their shares which was not true, but even besides the point of getting into who claims what, the real issue is this person was very upset that a private conversation was shared publicly. Thats the issue here, as you broke someones trust and privacy. I understand you have your interpretation of what is fair game, but that doesn't mean the person youre conversing with feels the same. Common courtesy and common sense should prevail here, again i dont think thats unreasonable.