John Greenewald has spent his life trying to pry secrets out of the US government. Now, he’s asking for some help to get his hands on some of the most elusive documents he’s ever tried to nab.

On Wednesday of last week, Greenewald, who runs the declassified-document clearinghouse the Black Vault, started a crowdfunding campaign on GoFundMe to raise money for the fee the Central Intelligence Agency is charging him for his latest Freedom of Information Act (FOIA) request. He’s hunting for documents related to the notorious MKUltra program (often referred to as the CIA's "mind control" project), an endeavour he embarked on after realizing that the agency had left out thousands of pages from a FOIA request Greenewald filed about the program back in 2004.

The fee, based on reproduction costs set at ten cents per page, comes out to $425.80. Greenewald said he was denied a waiver, usually given to members of the media or FOIAs that pass a public-interest test. “There’s really not much I can do besides cut the check,” he told me over the phone.

As of Monday, he’s over halfway toward his fundraising goal, which he set at $500 to account for GoFundMe fees and potential surprise surcharges.

MKUltra was a covert CIA program launched in 1953 to study the effects of drugs and chemicals on human behavior. In particular, American spies were interested in how they could induce states such as hypnosis, amnesia, and even physical paralysis. It was a Cold-War effort to keep up with the Soviets, whom the CIA believed were using such techniques to brainwash Americans. As part of the program, unaware test subjects—often marginalized people like prisoners and sex workers—were dosed with drugs such as LSD and secretly observed.