
SEC Involvement
I'm not sure that they could complete any pending mergers or acquisitions of public companies if they know that vital information has been taken. There are very strict laws and regulations around M & A confidentiality, and as Martha Stewart learned the hard way, these can involve prison time.
Also, seeing as how you can make tens of millions of dollars from "insider" trading (and yes, a crook stealing the information is now legally an insider), they could have probably made more money by not encrypting the data, thus giving their break in away, and just putting money into the stock market. Might be trickier to hide your identity, but it can be done.