I don't remember a case of that happening in the few years I've been participating here, but there has been instances where posters with questions have been cautioned about having given too much information. i.e. a link to their listing that they either want to sell or buy, how much they realistically would pay or accept if different from list price, how pressured they are by a deadline of some type making them desperate to sell....things that could lessen their bargaining position should the other party know of it.

Not that I've seen. I've always been careful to not link to my listings or say very specifically where I live. But a few years back, a forum member connected some dots (through some offline loopholes that I quickly closed when I discovered them) and actually emailed my realtor with a link to an old GW post where I was asking for help on a problem with the house that was eventually solved by the contractor. His email implied that the house had defects and questioned the price.

Yeah, some people have too much time on their hands.