Providing too little information or context when blogging or tweeting. With the ubiquitous status updates on Facebook and Twitter, people forget that it can be helpful to provide enough context for a message to be meaningful. So, ironically, while people tend to overshare, they also undershare at the same time!
Guy 1: I got a tweet last night from Jim, he said, "this is so effing great!"
Girl 1: I saw that, too. Why does he constantly undershare?!
Guy 1: Probably wasn't that great.