When a person buys weed off the street, there is no way they would exactly know what dangerous substances are cut into it. On the other hand, current legalization efforts create a framework for a safety control system, which will work to get rid of the risk coming from smoking marijuana. On the streets almost every year someone produces a bad batch of some sort of drug and users O.D. Like last year there was a bad batch of heroin in Indiana it apparently had elephant tranquillisers in it and everyone start dropping like flies.