Your worst boss ever did what to you or to a co-worker?

The biggest idiot boss that I ever had was when I was in my twenty's. I worked part time in a supermarket and was locked in the store on Christmas Eve after closing. I was stuck there for a few hours until the police finally tracked him down in a bar.

My boss hired her friend who had NEVER had a job in her life, and told me to train her. So I listened and did my due diligence to train this moron, only for her to take my job 3 weeks later.

Worse boss ever was considered a Caustic Boss by modern day definitions.

His "Day to day" expectations depended upon what kind of day, week, month he was having. The range was from moderately antagonizing to outright belligerent. He would walk into the office and throw computer hardware as close as possible to us while we were engrossed in working trying to scare us . . . We weren't allowed to surf on the internet, and were expected not to waste time, yet we were summoned at least 4 times during the day to look at a YouTube video he found . . . Usually regarding some truck driving through mud . . . Or some antique car restored. He would often tell us to do one thing . . . Then when realizing it was a bad idea, blame us for being so stupid for coming up with the idea, once we did his bidding.

Two occurrences speak specifically to his management style. 

1. When I first started, I pushed to get a virtual environment in place. It was a great way to work on a system's hardware with a virtual machine in place to fulfill the role in the production environment. He told me this was a stupid idea and that they were never going to strive to be so "Cutting Edge" . . . 3 years later, we put in a virtual server to do just what I proposed to work on some critical hardware. After it was successful, he said, "Well that was slick, I am now going to receive praise from our director of a job well done . . Oh, and (he looked at me) I know this was your idea, but I will have no problem receiving full acknowledgment for it."
2. There was an issue with one of our server's completing a full backup within the allotted time. Each of the network administrators (including him) took a turn at trying to resolve this issue. He had mentioned that he had been able to shave several hours off the backup time from what he did . . . One week later we lost a the drive assembly containing all 3 Hard Drives affectively destroying the RAID and thus all data. Upon  spending hours through the night rebuilding the system's hardware (Not him, me and another Admin), then building new RAID, we tried a full recovery off of the latest back up . . It was at this time, we discovered that the SQL agent had been shutoff on the backups, and no copy of the data base could be recovered.  We were brought in front of the CFO to explain why the database was not backed up . . It was at this time that this bastard of a boss, said that I was responsible for all back ups, and the secondary person responsible was the other Network Admin . . . We were both told to take a week off with no pay, we received a letter in our file. There was nothing in my job description regarding my being solely responsible for back ups, and he was the last to work on the issue . . .

Although at many times he had mentioned that as a Manager Everything was his fault, I had never seen him take any blame for anything . . He was quick to throw us up as meat shields against the fray of bullets, or completely throw us under the bus . . . I added possible 10 years back to my life by leaving that job.