How's this for bad practice. I needed to restore a dev database, so intended on taking it offline prior to the restore. Like a fool I was multitasking, and on one monitor had an instance of of SSMS connected to our live server to do some reporting, and on my other monitor a second SSMS connected to dev. Our dev database had the same name as our live database, guess which one got taken offline!

It took about a minute to realise what I had done, by which time we had taken our 6th call from users who had been kicked out of our main 'line of business' system

We blamed the shoddy network for dropping out 😉