rm -rf /+(?)
If anyone not understanding the joke, + character matches 1 or more instances, and (?) matches any one character. And / is start of entire filesystem. rm is remove. -rf (recursive, never ask verification). So it removes every file that you have rights to remove.
You can also do same thing accidentally by proxy. When my first computing teacher asked entire class to write anything to terminal to show that you had to write specific commands and computers don't understand normal language. Then she told to press enter. I asked her if she was sure. She asked why. I said that I wrote "format c:" . I have never seen teacher walk so fast in a classroom. I think that was last time she used that line in the classroom.
I also think about the response to it. Sure it sucked that it happened, and someone was probably feeling really bad about it. But it was a learning opportunity as well. Not just for them, or AWS, but for everyone in tech. Put those safety nets in place.
It was a good operational lesson and one I'm happy to see shared still. If a command will let you perform a self-inflicted wound like that without checks, then it's time to review that command. Err on the side of caution and bias towards minimizing blast radius even if it means sacrificing some speed. "Move fast and break things" may be true at times, but not when the "*" character is ever involved. =)