Gaslightning

A form of intimidation or psychological abuse, sometimes called Ambient Abuse where false information is presented to the victim, making them doubt their own memory, perception and quite often, their sanity. Often erroneously called "gaslighting". The classic example of gaslightning is to switch something around on someone that you know they're sure to notice, but then deny knowing anything about it, and to explain that they "must be imagining things" when they challenge these changes. A more psychological definition of gaslightning is "an increasing frequency of systematically withholding factual information from, and/or providing false information to, the victim - having the gradual effect of making them anxious, confused, and less able to trust their own memory and perception.