Jeffrey Segal, a retired neurosurgeon, launched Medical Justice 10 years ago to fight frivolous malpractice suits.  He now encourages doctors to require patients to sign a "mutual privacy agreement" before treatment to prevent patients rating them on Web.  By signing, the patient promises not to post critical comments about his or her care on the Internet without the doctor's permission.  Segal says it is a lack of oversight and accountability on the Web sites that troubles doctors.  "People are free to post any type of commentary," said Segal. "Most of these sites have only two, three, four reviews on a physician. There's no verification that the person was a patient. They could be a disgruntled employee, an ex-spouse, a competitor -- anyone trying to create some havoc."