When prosecutors earlier this year filed murder charges against a physician for prescribing to patients who overdosed, Los Angeles County Dist. Atty. Steve Cooley said he was also sending a message to other "Dr. Feelgoods" who over-prescribe. Some physicians fear the crackdowns in Los Angeles and other parts of the country could have a chilling effect on the way doctors work and end up making patients suffer needlessly. They also worry authorities are holding doctors criminally liable for the behavior of their patients.