BBC News By Paul Pigott image captionThe substances mimic the effects of illegal drugs such as ecstasy and cannabis Psychoactive drugs such as Spice are easier than ever to buy, despite a ban which came into force five years ago, drugs charities have warned. They said trade had gone to the dark web, making them "more available" and "more dangerous" for problem users. Since it became illegal to make, sell or supply such drugs, just 28 people have been convicted in Wales. The Home Office said the new law had "eliminated" the open sale of drugs in shops and on UK-based websites.