Some of our PPC clients have asked us which products are forbidden on Google Adwords. We have put together a list of must not advertise on Google and we suspect the list is pretty much the same for yahoo and Bing.
• Drugs & Drug Paraphernalia
No selling weed, crack, meth, magic mushrooms, LSD, or any other mind-bending substances via PPC. You also can't sell bongs, glass pipes, and other getting high accessories... except for black lights, those are still ok.