One detail in ESB has always perplexed me - maybe the more learned SW scholars here can help...

When Han et al land on cloud city, C3PO has a run-in with someone in a room, and gets blasted to pieces. What is the significance of that scene? Who blasted him and why? What is it supposed to portend? About all I get out of it is that the city is more dangerous than it looks... I always assumed that he must have gotten blasted by a storm trooper or something - but why would the storm trooper blast 3PO and just leave his bits lying around? Wouldn't that raise suspicions?