Those of a libertarian bent tend to support the idea of pill testing at places where youth gather to do things like listen to doof doof music so tedious that they must take mind altering illicit drugs in order to enjoy it for more than 10 minutes.
Yet, as I have seen argued before, this is a position motivated more by ideology than evidence that pill testing is effective. [I'd link to my previous post about it, if only Google wasn't so pathetic in its erratic indexing of this blog.]
The latest article explaining this was at the SMH today. Basically, the testing is far from being very accurate, and even if does identify a substance that is safe at small doses, it can't tell what the dose is.
Sounds pretty convincing to me, even if I have an ideological position against recreational drugs generally.