Modern justice systems depend primarily on material penalties—fines and/or imprisonment—but Romans seem to have taken the shame of infamia seriously. Sometimes, however, they did exploit what look like loopholes in the law. In 19 C.E. a woman named Vistilia figured out that she could avoid the penalties for adultery by registering with the aediles as a prostitute. Prostitutes, whose business was perfectly legal, were naturally allowed to have sex with whomever they pleased. The case became quite notorious because Vistilia was from a prominent family, and the Senate decided that she should be punished regardless of the law and that noblewomen should in the future be prohibited from registering. Still, they seem to have been surprised that the more concrete penalty was needed.

Source The Annals of Tacitus, translated by D R Dudley (NewYork New American Library...