It's been a while since I was on the club scene, but I guarantee you that there were pills doing the rounds in Birmingham clubs around the turn of the millenium that were laced with smack and ket, I can't speak for other places, and I don't know about the present time. It's the prime reason I stopped taking pills and started taking MDMA powder with me to gigs.

People should test their pills, but this is not easy to do while it is illegal.