It does constitute insider trading if the person has access to...

It does constitute insider trading if the person has access to information not available to the general market and trades on that information. The ones who usually get caught are the smart alec ones who skite about their inside knowledge particularly in a public forum. It attracts attention of disgruntled or ethical investors who in turn then provoke ASIC into carrying out an investigation. Posters can be as negative as they like on a stock but to claim they have inside knowledge and post it, is outrageously unethical and should not be allowed.