i think doctors should be permitted to use the search to decide whether they want to treat a patient at all, based on certain criteria. For instance, if you find the patient ranting about three other doctors and claiming to be in litigation with hospitals over various perceived slights... maybe they want to steer clear. Maybe the person really has a terrible track record of bad doctors and hospitals, but I fear the loss of physicians because of false accusations and public airings of disagreements.
However, I think using it for additional diagnostic data seems dodgy. There are too many ways that can go south. What's physically present, medically recorded, and obtained directly from interview should constitute much of the initial sphere of information.