BTW: from what I understand, the company dictates this, not the FedGov. The company I work for used to work like this, then they changed their system and now I can move funds daily.
That's the way it was with my company...a few times a year they were allowed to trade for a couple weeks. Some did...some didn't ...the stock went down to nothing and we are off the market. Some employees lost thousands...some made thousands. That's life.
Enron was going down hill since the Februrary of last year...surely they had many windows to sell.