TechKnow Sydney, page-263

Thinking a bit more about this.

Share trading takes place in a highly regulated environment.

I believe that the default assumption HAS to be that anything Brian or Tony tells you, whether in an apparently "private" conversation or in a public forum like TechKnow, will then appear on HotCopper, the Fin Review, the local pub etc.

Otherwise, they are conveying apparently privileged information to you specifically, which you can then act on and gain a benefit. This is more or less the definition of insider trading, which can have significant ramifications. I am sure that neither you nor the officer of the company want any implication that this is taking place. Therefore, this cannot be a chat between two "mates", to be kept private. In fact, it is probably a good idea if it is publicized.