A lot of people still do not know that posting of a tweet on Twitter could be used against them in a court of law in legal proceedings. What you publish on Twitter is public information which is available on public computers and could be used in legal proceedings. However we still do not have yet a documented case where Twitter tweets have been used in any decisive court proceedings. However its only a question of time when such an exercise start happening. Therefore people would need to be extremely cautious and careful of what they post on Twitter. Twitter as a phenomenon will evolve from a casual phenomenon to a more serious micro-blogging platform as time passes by.