The thing that confounds the situation a bit, for a large quantity of people, is that in certain industries and in certain roles, a huge number of people are considered insiders. For example, anyone at a corporation who can access sales or booking data is an insider ... including the poor CRM administrator in IT or the exec admin in the Sales office. Beyond that, though, in financial services firms it's entirely possible they might consider all employees insiders on all equities. Fidelity does this, for example, and they additionally require all employees' equity holdings solely to exist in Fidelity-managed accounts so they can actively audit for insider activity.

This second case seemed more nutso to me than the first, but both are true -- I've lived them.

Only made public some time after the trade occurs.