This is a true story when I was working as a application technician a couple of years ago!

Before I started working there, they had a couple of incidents with ppl with less knowledge accidently deleted stuffs in prod databases, and only a handfull of ppl get the full access to them. I started working in this team, and one day I was asked to run a snippet in one of the prod databases from a co-worker with less privilege.

Loged in, run the snippet and the server STALLED for a couple of minutes! When the snippet was finished I looked at the screen and saw the output "1724217 rows deleted". The fun part here, was that we went to a coffee break right after this, and after a couple of minutes we started to hear ppl mumbling that the network was slow as f*ck, servers didn't respond etc etc.

Well, I responded that I got a snippet that deleted 1724217 row in a table and we ran back to our computers and started to work backwards to solve this.

The best part in this story is that:

* Was not my fault! Even thou I was the one that executed it.
* The tables was deleted from a live prod server that was not heavily used!
* I asked for a life line for us in this team, that we needed a prevented output so we can "match" the actual output after we ran it in prod from the ones from the developers!

Even thou it was not my fault, this is the worst mess up I have done working in IT over 10 years. O_o