I am an old fogey and not up on the drugs kids are doing these days, but Spice seems to be causing issues serious enough to get headlines (at least around here several deaths and hospitalizations by the dozens), so came on my radar that way. It's some kind of
synthetic marijuana but unlike actual pot, can cause hallucinations, delusions, violence, and sudden death.
No regular old stoner I have ever known would want a high that includes anything like that...they want to chill out and laugh. WTF is this about?
ETA: The toxicity is probably related to and varies with the manufacturing processes. Like any back-shed lab made drug, there is no way for users to know exactly what they are getting.