Why Are Numbers Being Leaked Early? (MSFT, DIS, NSC)

Fool me once, shame on you. Fool me twice, shame on me. Fool me three times, what the heck? Microsoft MSFT just released earnings much earlier than anyone was expecting, reporting earnings of 77 cents per share on revenues of $19.95 billion. This has happened a couple of times before, with Norfolk Southern NSC earlier in the week, and Disney DIS doing the same a while back. Is this going to be a trend going forward, with companies releasing earnings during the course of trading? Is there something more behind this, other than an error at the press release company or with the company? Time will tell, but this seems to be a concern for investors, and the markets in general.