The act of spying upon a person to satisfy one's sexual desires can be classified under which term?

The act of spying upon a person to satisfy one's sexual desires is classified as voyeurism. This term specifically refers to the practice of deriving sexual pleasure from observing others engaged in intimate behaviors, often without their consent. Voyeurism is distinct in that it emphasizes the sexual aspect of the observation, which differentiates it from general acts of spying or surveillance that may not have a sexual motivation.

Peeping can refer to looking at someone illegally or without consent but doesn’t inherently imply a sexual motivation. Surveillance generally pertains to the monitoring of behavior or activities, often for security or investigative purposes, and is not necessarily sexual in nature. Invasion of privacy is a broader legal concept describing scenarios where someone's personal space or privacy is violated but may not specifically relate to sexual behavior or desires. Thus, voyeurism captures the essence of the question as it directly ties the act to the satisfaction of sexual desires through non-consensual observation.