Since 1990, making, selling, or even owning a bong has been federally ruled illegal -- that is, it's illegal in all fifty states regardless of local laws. Sellers and manufacturers are also subject to prosecution as Racketeer Influenced and Corrupt Organizations (RICO's), and have been charged and successfully prosecuted on money laundering charges too. This law was held up in 1994 by the Supreme Court of the United States in the case US v. Pipes and Things, and is now an indisputable part of the law.

To get around this, the head shops in my area refer to the equipment they sell as "contemporary tobacco smoking accessories" in all of their advertising and stores -- even the term "water pipe" was deemed to be too nonspecific to be safe. Unfortunately, in the aforementioned case it was ruled that selling any kind of water filtered pipe, under any terms, was illegal. Since the DEA is busy harassing people all over the world, they don't usually have time to bust mom-and-pop head shops, some of which don't even know they're violating a federal law. Thus, calling the bongs contemporary tobacco smoking accessories doesn't make any difference at all, at least on the federal level; at most it might keep them from discovering the individual stores for a little while.

I've always thought that the phrase "contemporary tobacco smoking accessory" is such a mouthful as to make it hilariously funny to say out loud when enhanced with an appropriate level of irony. I (and those friends who have caught on to the humor) now refer to all of my toys as CTSA's. Funnier still, if you use a contemporary tobacco smoking accessory to smoke something, then logically you must be smoking contemporary tobacco. Thus, whenever I need something out of my little glass jar, I mention that I'm going to go get a bowl of contemporary tobacco. Head shop people must have figured out this joke too, because when I've shopped for pipes and asked how well it smokes contemporary tobacco, the clerk laughed both times.