Tags are keywords. I put tags on every post to help you find the content you want. Tags may be people (Dominic Raab, say), organisations (The Howard League, PRT), themes (women offenders, homelessness) or specific items (heroin, racial disparity, ROTL). If you’re looking to research a particular issue, they can be invaluable.
It seems likely that the relative ‘drought’ of ecstasy on European markets in 2008–2009 was caused by successful international cooperation and law enforcement efforts in both Europe and Asia that targeted the suppliers of the main ecstasy precursor, PMK.