Uploading a video to an event page and swapping out the ID code could have allowed computer savvy hackers to overwrite any Facebook video, no matter who uploaded it. Dan Melamed, a security researcher, uncovered the vulnerability — and earned a cool $10,000 for showing Facebook the error.

Melamed found the vulnerability last June, but only shared the glitch Monday after a Facebook update had already corrected the issue. By attaching any Facebook video to an event post by grabbing some of the code and pasting it in while uploading another video, that stolen video pops up on the event page.

But what’s even more unnerving is that when that stolen video post is deleted, the original is also deleted from the owner’s page. Disabling the comments on that post through the event page could also disable comments on the original video.

Melamed reported the vulnerability to Facebook at the end of June — a day later, the social media platform asked him to delete one of Facebook’s own videos to prove the glitch, and the next day, that’s what he did. Two weeks later, Facebook awarded him $10,000 for responsibly reporting the error.

Melamed is a self-described security researcher and web programmer — he hacks into programs to find weaknesses, then reports them to the company to fix before a hacker exploits the glitch. While the security issue was uncovered months ago, Melamed only shared how he was able to delete any Facebook video after Facebook removed the vulnerability — so hackers couldn’t use his findings as a how-to guide. He did not say when Facebook corrected the issue.

The video fix comes after a different security researcher discovered how to delete any Facebook album using only four lines of code — Facebook fixed that glitch within two hours. Facebook uses a Bug Bounty program to encourage hackers to report rather than exploit any uncovered weaknesses. Now five years old, Facebook has paid over five million dollars in “bounties” through the program.