Bongs are considered as drug paraphernalia, but simple possession is not considered a federal crime. However, in some states – such as North Carolina – owning a bong is illegal. Police will check for drug residue, and if you used the bong to smoke illegal or controlled substances, you might face drug paraphernalia charges. Note that even if bongs are legal in some states, they are still illegal under federal law. Thus, selling them might land you in trouble with the authorities.