I’d be surprised if the final decision on this is anything other than the rule that’s existed with e-mail — that if it’s on a company computer, it’s not private and your company has the right to access the information. Even though we all “know” this by now, or should, it takes cases like these to remind us there is never any real anonymity or privacy in Web-based communication — and if you’re using a company-owned smart phone or computer to conduct illicit communications, well, you are doing so at your own peril.
It will be interesting to see how the official ruling turns out.