Electronic harassment, electromagnetic torture, and psychotronic torture is a conspiracy theory describing the hostile use of mundane electromagnetic devices, such as radio or microwaves, against self-identified "targeted individuals" (TIs). They believe that malicious actors are transmitting sounds and thoughts into people's heads, affecting their bodies, and harassing them generally. The delusion often concerns government agents or crime rings and alleges that the "perpetrators" use electromagnetic radiation (such as the microwave auditory effect), radar, and surveillance techniques to carry out their goals.

Some TIs claim to be victims of gang stalking, and many have created or joined support and advocacy groups.

Multiple medical professionals have concluded that these experiences are hallucinations, the result of delusional disorders, or psychosis.

The experiences of people who describe themselves as undergoing electronic harassment using esoteric technology, and who call themselves "targeted individuals" ("T.I."), vary, but experiences often include hearing voices in their heads calling them by name, often mocking them or others around them, as well as physical sensations like burning. They have also described being under physical surveillance by one or more people. Many of these people act and function otherwise normally and included among them are people who are successful in their careers and lives otherwise, and who find these experiences confusing, upsetting, and sometimes shameful, but entirely real. They use news stories, military journals, and declassified national security documents to support their allegations that governments have developed technology that can send voices into people's heads and cause them to feel things. The New York Times estimated that there are more than 10,000 people who self-identify as targeted individuals.

Psychologist Lorraine Sheridan co-authored a study of gang-stalking in the Journal of Forensic Psychiatry & Psychology. According to Sheridan, "One has to think of the T.I. phenomenon in terms of people with paranoid symptoms who have hit upon the gang-stalking idea as an explanation of what is happening to them". Mental health professionals say that T.I.s can experience hallucinations and their explanations of being targeted or harassed arise from delusional disorders or psychosis. Yale psychiatry professor Ralph Hoffman states that people often ascribe voices in their heads to external sources such as government harassment, God, or dead relatives, and it can be difficult to persuade these individuals that their belief in an external influence is delusional. Other experts compare these stories to accounts of alien abductions.

Press accounts have documented individuals who apparently believed they were victims of electronic harassment, and in some cases persuaded courts to agree. In 2008, James Walbert went to court claiming that his former business associate had threatened him with "jolts of radiation" after a disagreement, and later claimed feeling symptoms such as electric shock sensations and hearing strange sounds in his ears. The court decided to issue an order banning "electronic means" to further harass Walbert.

Various people who describe themselves as undergoing electronic harassment have committed crimes, notably including a number of mass shootings.

Fuaed Abdo Ahmed, a 20-year-old man, held a man and two women hostage at the Tensas State Bank in St. Joseph, Louisiana on August 13, 2013, eventually killing two of the hostages and himself. A subsequent police investigation officially concluded that Ahmed had paranoid schizophrenia and was hearing voices. Ahmed had accused the family of his ex-girlfriend of implanting a "microphone device" of some kind in his head.