All right, so for "people" substitute "48 MBA students," but I in this case, I'm not being sarcastic. A paper from researchers at Lehigh, Rutgers, and DePaul found that their study subjects were more likely to intentionally deceive others while communicating via email, and felt justified in doing so. I can't really sum the paper up any better than the Science Daily author did, so I won't try, although I haven't yet read it fully for content.
Not really a huge surprise to those of us who have been around since more or less the dawn of the tubes, and I don't believe that this is a new trend, despite what some folks might say. I suspect even the most well-intentioned folks might say things in an email that they wouldn't even consider saying to somebody's face, and we all know about the internet tough guy / bully.
What does this mean for those of us who live and work by email? We need to be extremely careful about what we send, and carefully read what we receive. Writing clearly and concisely is as important now as ever. This reduces the risk of misstatement or misinterpretation. Reading for content is similarly critical, although always approaching what others say with suspicion is probably not the correct approach.
This emphasizes the importance of face to face communications; I think that the better somebody knows somebody else, the less likely they are to deceive, either intentionally or unintentionally. There are always the edge cases, but they'll be assholes regardless of the situation. The best we can do is to protect ourselves.