Why are companies so opposed to regulations?

As far as the economy goes, one of the difficult words to hear is "regulation" (at least thats what it seems). My question is why would government imposed regulations be a negative? Because lack of regulation you could argue led to the trouble we are in today and the "laissez faire" attitude sounds great, but you can't just let people do whatever they can get away with because corruption, greed and stupidity will propogate wildly if not contained.