One thing that never ceases to amaze me is how marijuana, which by most accounts is pretty harmless, is illegal, yet many of these synthetic drugs are completely legal and sold over the counter at gas stations and head shops, despite being very harmful.
The reason for this is because as soon as the government makes one type of chemical compound illegal, the chemists simply make a minor tweak to the recipe and are now completely legal again. It seems the USA is a bit stricter than some of the rest of the world in terms of legal highs and experimental drugs or compounds, however it seems worldwide every government is trying to crack down on these.
In the UK the British Government is trying to outlaw more of these substances in response to a growing number of news reports about overdoses on these synthetic drugs. This documentary follows some individuals who are hooked on these harmful substances.