The anonymous comment on the Web site RateMDs.com was unsparing: "Very unhelpful, arrogant," it said of a doctor. "Did not listen and cut me off, seemed much too happy to have power (and abuse it!) over suffering people." Such reviews are becoming more common as consumer ratings services like Zagat's and Angie's List expand beyond restaurants and plumbers to medical care, and some doctors are fighting back.

They're asking patients to agree to what amounts to a gag order that bars them from posting negative comments online.

"Consumers and patients are hungry for good information" about doctors, but Internet reviews provide just the opposite, contends Dr. Jeffrey Segal, a North Carolina neurosurgeon who has made a business of helping doctors monitor and prevent online criticism.

His company, Medical Justice, is based in Greensboro, N.C. For a fee, it provides doctors with a standardized waiver agreement. Patients who sign agree not to post online comments about the doctor, "his expertise and/or treatment." More here.