John Oliver is not very good at keeping secrets, but he’s very good at making a point. The comedian went on friend and fellow late-night host Stephen Colbert’s Late Show Monday night to discuss Donald Trump, and his latest deep-dive piece on encryption.

Oliver managed to summarize the issue well, crack a few jokes, and mistakenly reveal his iPhone passcode to the entire world on live television.

“I’m on the side of encryption, personally,” Oliver said, to which Colbert immediately asked him, “What are you hiding?”

“I’m not hiding anything!” Oliver protested, laughing, and Colbert shot back.

“Well we’ll never know now, we’ll never know whether you’re hiding anything, because you won’t let us look at your phone.”

Oliver, still chuckling, handed Colbert his phone. He mistakenly pulled his microphone battery pack out of his pocket, then mimed passing the battery pack as if it were his phone.

“Here you go, the code is 4873,” he said, and then immediately recoiled, as Colbert, leaning forward with a look of predatory glee on his face, exclaiming, “Is that really the code to your phone, 4873?”

“Well, not anymore it’s not,” Oliver replied. But he used the hilarious example to make his point.

“Security is difficult, ‘cause you make mistakes, like reading out your phone’s passcode on live TV,” Oliver said. “That’s the point, it’s hard to keep things secure. In a sense I’ve won the argument through incompetence.”

But Oliver’s point is well taken. Weakening the encryption on Apple’s products could make millions of customers vulnerable to hackers and foreign governments — not to mention our own.

Photos via CBS