I generally identify as an empiricist and a skeptic. I’m not really interested in wild stories or fantasies. I want to know how the world really is.

But uncovering the truth isn’t always as easy as it seems. It’s easy for skeptics to fall into the habit of discounting any seemingly fantastic claims we might come across. If it seems like a conspiracy theory, rather than digging for the real truth, we simply write it off.

But we could all do with a healthy respect for conspiracy theories. Far too many seemingly fantastical conspiracy theories have turned out to be true — and many remained secret for decades before they were exposed.

Remember the stories about the CIA doing experiments on unwitting American and Canadian citizens? Turns out that actually happened. It was a program called MKUltra that ran from the early 1950s to the 1970s before it was revealed by the Church Committee.

How about government health organizations performing experiments on black men with out their consent? Yeah, that happened too. The Tuskegee Syphilis experiment, in which Black men previously infected with Syphilis were studied, rather than treated, with out their knowledge or consent. That one ran from the late 1930s to the 1970s before it was exposed in mass media and shut down.

How about the FBI secretly harassing and disrupting left-leaning political organizations? Also happened. An FBI program called COINTELPRO involved the infiltration, harassment, and disruption of numerous left leaning political groups, including the civil rights movement, the anti-Vietnam movement, the black power movement and many more.

A mass, high level conspiracy to sabotage political opponents? That happened too. You might have heard of it. It goes by the name Watergate. These days it’s referred to as a “scandal” and spawned a whole trope for the naming of political scandals. But in actuality, it was a conspiracy.

A US administration violating US laws and treaties in order to fund foreign guerrillas? Check: Iran Contra. (Also referred to as a scandal by the way, instead of a conspiracy.)

US security agencies committing dragnet surveillance of US citizens? Yep. Edward Snowden let us in on that one. That one’s even alluded to in the meme and is used to dismiss the idea of mass conspiracies. The meme fails to mention that it was happening for a decade or more, involved multiple, massive intelligence agencies the world over, and was treated as just another conspiracy theory until Snowden blew the whistle.

How about an entire industry conspiring to muddy the science with respect to the harms of its product? That’s happened numerous times now. It was most famously done by the tobacco industry. Noami Oreskes documented numerous instances in her recent book, Merchants of Doubt. More recently we learned that Exxon has done it with Climate Change.

In many of these cases the conspiracy in question was on-going for a considerable period of time before being publicly revealed and acknowledged. MKUltra ran from the early 1950s to the 1970s and was only revealed in the Church investigations. We still don’t know the full extent of it, because the CIA destroyed most of the documents pertaining to it, rather than hand them over to the Church committee.

COINTELPRO similarly ran for almost a decade before being revealed and shut down. It wasn’t the media or the government that revealed it — it was a group of activists breaking in to FBI headquarters at enormous personal risk, stealing documents, and handing them off to the media that uncovered it.

These are just some of the many conspiracies which the media has uncovered or the government declassified and admitted to. There are others that are supported by credible bodies of evidence and substantive allegations that have never been fully uncovered.

Like allegations that a large group of business leaders conspired to overthrow the Roosevelt administration and replace it with a fascist government in the 1930s. The man they picked to be the dictator went straight to congress after they supposedly asked him. A congressional committee found his testimony credible, but the investigation ended there. The incident is referred to as the Business Plot.

Then there are the allegations of CIA drug trafficking in support of the Contras. The CIA still denies this one, but multiple journalists have turned up substantive evidence backing the claim. Most famously, Gary Webb in his report for the San Jose Mercury News titled Dark Alliance.

In both these cases, we still don’t know the real story. But there is enough evidence that it should lead most people to be skeptical of the official story. Instead, we’re usually encouraged to discount and dismiss these allegations, and others like them, as wild conspiracy theories.

But history has borne out that many wild conspiracy theories are basically true. Many more have at least a nugget of truth to them. Even if that nugget isn’t necessarily a conspiracy.

When faced with a conspiracy theory, it’s important to remember just how many of those theories turned out to be substantive. It’s important to think about the incentives and power dynamics at play. Skepticism is very important, but it’s also important to direct that skepticism at the right people and institutions.

Instead of ridiculing the powerless, we should remember to be skeptical of the powerful. The conspiracy theory might not have the truth of the matter, but it might be identifying a thread that needs pulling. Sometimes we need a little less Snopes and a little more Woodward and Bernstein.