Crimes against chastity are crimes now most commonly prosecuted in the Islamic states according to sharia law nowadays, but such crimes have been prosecuted all over the world throughout history. They are, where prosecuted, usually treated as the gravest of crimes, usually punishable with the death penalty.
They include but are not limited to the following sexual acts, defined as such in the jurisdiction where they are prosecuted:
On April 6, 1967, birth control advocate Bill Baird was arrested in Boston, Massachusetts on charges of "crimes against chastity" for holding a lecture on birth control at Boston University and giving an unmarried female a condom and a contraceptive sponge. Baird served three months in prison but, in 1972, won a Supreme Court case, Eisenstadt v. Baird.
Massachusetts continues to have laws on "Crimes Against Chastity, Morality, Decency and Good Order", which includes laws against providing contraception or information on contraception to unmarried persons (Chapter 272, Section 21 & 21A), but the latter are now a dead letter.