No need for (b) typos and (c) trolls, but (a) opinions are output that computers currently fail to effectively provide, but things that much of human society currently depends on. I was going to cite medicine and marketing as examples, and act like science doesn't depend on opinion, but that is actually very false. The scientific process is basically 1) experiment/observe (i.e. take pictures), 2) form opinions (calling them "hypotheses") about what we observe and 3) decide what to do next to convert that opinion into a truth value.