The pill is legal. The actions taken while on it are not.
Yet defendants have found relief in court thanks to the "Ambien defense," a statement that they cannot be responsible for actions taken while under the influence of the drug, used by 44 million Americans, according to the San Jose Mercury News.
Kevin Robertson of Santa Clara used the "Ambien defense" to explain why he awoke behind the wheel of a crashed automobile, with no memory of the event, according to the newspaper.
Sleep-driving has affected people big and small: former Congressman Patrick Kennedy crashed his car while on the drug in 2006, the newspaper reported.
The Food and Drug Administration said in 2007 that Ambien can cause "complex sleep-related behaviors" including "sleep-driving, making phone calls and preparing and eating food (while asleep)," the newspaper reported. Specifically, sleep driving is "driving while not fully awake after ingestion of a sedative hypnotic, with no memory of the event," the newspaper reported.
But every case appears to have a different tolerance for the defense -- in Robertson's case, his acquittal may be thrown out by a parole counselor (he's on parole for bank robbery, the newspaper reported).