ChEck iT! has organised a series of events at the last event on 10.03.2011. substances of health concern tested. Among other things, two years ago Tablets sold as ecstasy be warned. Also three samples sold as speed  were categorised as being of particular health concern, as other psychoactive substances were identified in addition to amphetamine. Two warnings were also issued due to powder passed off as "cocaine". posted. Both samples contained - as is now unfortunately not uncommon - levamisole and phenacetin, among other things. You can find a detailed description of all the warnings and the unexpected ingredients here here.