Which do you think more people would lie, online or face-to-face? Here is an interesting talk by Jeff Hancock on TED.
Although it is scientifically true, what he finds seems to be needed more evidence in order to prove his insistence, I think. For instance, people more easily write like "I'm on my way" on twitter than other social media or email, because tweets are usually assumed as not serious even if some of them lie or overstate.
Anyway, this is very inspiring!!