"Have you looked at the "IP check" feature on various posts?"

No, not in this case.  I'm thinking about those instances where a poster may use a single alias on one message board, and different single-use aliases on others.  Indeed, there is nothing wrong with this, generally speaking, a lot of people do it.  I am merely mentioning that I've sometimes suspected insiders of using different aliases on different boards (related to the same company) to help hide what they are doing unethically, if not illegally.  As you can suspect, the discovery of such behavior can lead to ruined careers, lawsuits, and broken relationships just to name a few adverse consequences.  And all those postings that show up on message boards and other computers around the world can never be erases, meaning all those aliases can be tracked back to the real person if needed.  It happens often.