Yesterday the Drug Enforcement Administration moved to axe the sale and distribution of three types of "fake pot," synthetic marijuana mixtures imported primarily from China and India. (Maybe you recall discussions about this from Demi Moore's 911 call after she OD'd on the ersatz ganj last winter.)
The Justice Department has classified the drug, sold on the street as Spice or K2, as a Schedule 1 after looking into the high number of hospital visits or calls in to poison control centers after its imbibing.
According to CNN, the most common negative reactions to the drug are vomiting, anxiety, hallucinations, seizures, high blood pressure, or loss of consciousness. The ban has been in the works since at least last year around this time, when the Village Voice's Runnin' Scared reported that while an overdose of real marijuana would never be fatal, one of the fake weed can be (although it's an extreme unlikelihood).