In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group burn plastic bags with spice, a synthetic drug, along with business cards that belong to spice pushers, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, one of which is swinging a bat at them in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group upturn the car that belongs to pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, one of which is swinging a bat at them in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group attack pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)

In this photo taken on Friday, March 15, 2013, members of a pro-Kremlin youth group douse with red paint two tied-up pushers of spice, a synthetic drug, in Moscow, Russia. Russian officials and anti-drugs campaigners say that spice has become one of the most dangerous drugs widely available to youngsters and almost impossible to ban because of the constantly changing chemical ingredients. (Photo by Alexander Zemlianichenko Jr/AP Photo)