a good point to raise. but I feel I should correct it a little bit...working at 7-eleven taught me this: if somebody comes in to buy smokes, and they don't have ID, ask if they're a cop or affiliated with the police. if they are with the cops, and they're trying to bust you for selling to minors, they are LEGALLY OBLIGED to say that they are police. if they claim not to be cops, then try to bust you, its entrapment.

this is Canadian law, BTW. always check your own regions laws and criminal code.