I pranked millions of Stack Overflow users with our prank - a paywall on copying from Stack Overflow! When users tried to copy from a question or an answer, they would get a prompt that they only had two copies remaining. If they clicked into the warning, they'd see a marketing popup for "The Key" by Stack Overflow - a keyboard that you could only copy and paste with given it only had the keys `Ctrl`, `C`, and `V`

The prank was immensely successful and a lot of fun. It was amazing seeing all of the reactions on Stack Overflow, Twitter, and Reddit.

https://stackoverflow.blog/2021/03/31/the-key-copy-paste/