Upskirting is the act of secretly or surreptitiously photographing underneath a woman’s dress or skirt. Because upskirting often occurs in public places, laws prohibiting the practice have been challenged on the ground that the victim does not have a reasonable expectation of privacy.

Laws regarding upskirting behavior—including photographing or videotaping a person in a bathroom or changing room—vary from state to state. In some states this conduct is prosecuted as a criminal offense under invasion of privacy, voyeurism, unlawful surveillance, surreptitious recording, disorderly conduct, or public lewdness statutes—depending on the state and its current laws.

Upskirting and the related criminal offenses for which upskirting may be prosecuted are located in a state’s statutes—often in the penal or criminal code.

In South Dakota, upskirting is considered a violation of privacy and is addressed under the state's voyeurism laws. Specifically, South Dakota Codified Laws (SDCL) 22-21-1 prohibits the act of 'secretly observing or filming another person, with lewd intent, in a private place without consent.' Additionally, SDCL 22-21-1.1 makes it illegal to disseminate images or recordings obtained in such a manner. While the term 'upskirting' is not explicitly used in the statutes, the described behavior falls under the broader category of voyeurism. The law recognizes that even in public places, individuals have a reasonable expectation of privacy concerning the areas of their bodies covered by clothing. Therefore, upskirting can be prosecuted as a criminal offense, and those found guilty may face charges that carry penalties including fines and imprisonment.