My sophomore year of high school, I was trying to writing a Discord (chat platform) bot for a server I shared with friends and unknowingly included the private key in a public repo I hoped to show them. A specifically written crawler for Discord keys found the key and starting spamming the server with images of very very undesirable things from the far corners of the internet at a rate of hundreds per second. Needless to say I learned my lesson the hard way.

Couldn't we use Google's bigquery to search for private keys?

Thanks for sharing! How do people write such crawlers? Do they specifically point them at Github repos?

The paper discussed in the article describes writing such a crawler. They simply use the GitHub search API.

When I attended Hack Reactor they did tell us not to push them. However since they didn't teach us git (they expected us to know it) many still pushed them up. You would know because they'd get an email from some random company/person letting them know that they found their secret keys and that they should enroll/buy their services if they don't know what they're doing. Luckily no one from my class got hosed, but others in the past had.