To be perfectly upfront, what we’re about to show you is not something we endorse. The legality of writing on U.S. currency isn’t clear-cut: according to Title 18 of the United States Code, Section 333 (18 U.S.C. §333), “whoever mutilates, cuts, defaces, disfigures, or perforates, or unites or cements together, or does any other thing to any bank bill… with intent to render such bank bill, draft, note, or other evidence of debt unfit to be reissued, shall be fined under this title or imprisoned not more than six months, or both.” The key term here is “intent to render” that bill to be reissued, which implies that it has to be taken out of circulation, and the bills we have included in this slideshow may very well be still exchanging hands. (Section 331 of the code, by the way, addresses the “mutilation” of coins, and as you can see here, the folks at the U.S. Mint have actually highlighted the word “fraudulently” in the text.)

That said, money graffiti is at the very least fun to look at. Some examples seek to make a political statement while others are only out for a laugh. Here is display some of the finest examples of this subversive art we’ve found online.