Acid isn’t all that dangerous. Fatal overdose is very, very rare, the only real risk is that someone will act on dangerous impulses, running into traffic or leaping off buildings, and when was the last time you heard of that sort of thing?
I’ve never used it because there’s a risk of a bad trip, which my friends have described as an afternoon in hell: can’t imagine any payoff would be worth that.
Nothing you can say to the authorities is going to change anything unless you have names of dealers to pass along. Nothing you can say to the users is going to change anything either, unless you have a personal relationship with them and can honestly express your fear that these unhealthy choices will have unhealthy consequences. So I see no upside to the risk you’d be running.
Now, if the issue is heroin, cocaine, meth or any other drug that’s highly addictive and commonly fatal, then by all means, get involved. But pot, hash, or acid? Frankly, I’d stay out of it.
Others will disagree, and that’s fine: maybe there really would be fewer drugs out there if we were all a little more pro-active.
But I’m of the opinion that it’s time for a major overhaul of the drug laws, de-criminalizing the safer substances, but getting very, very tough on the really dangerous drugs.