Spinning:v. The act of giving LSD or some other form of hallucinogen to people without informing the person or obtaining their permission. This is often done by either spraying the victim with a LSD/water combination, secretly placing a tab of acid onto their body or lacing their food/beverage with some form of entheogen.
I have heard of this occuring at phish shows and Reed College parties though I have never experienced it personally.