One of the funniest ongoing threads on Quora, the wonderful question-and-answer web site, is, "What is the most catastrophic mistake made by an intern at a tech company?"

Among the people who have answered the question are former interns at Facebook, Microsoft and AIG.

Their confessions include being rude to Mark Zuckerberg's wife, burning down an office building, and accidentally turning off the internet across large stretches of the Ukraine.

Some of the respondents have used their real names. We've excerpted and anonymized the best of their answers.

Enjoy.

This Facebook intern trolled Mark Zuckerberg's wife.

While I was interning at Facebook we were testing Facebook Questions shortly before the official launch. I decided to answer few questions, just to see the flow. The second or third question was from a girl asking 'How to solve quadratic equations?'. Since I'm a big fan of?XKCD?[a sarcastic comic strip] my instant response was 'Have you tried logarithms?' (xkcd: Impostor) and I decided to actually write it. Well, after all, as any such platform it was expected to have trolls so it was still valid form of 'testing' and I thought it's not that bad. That is, until I realized that Priscilla Chan, the person who asked the question, was Mark Zuckerberg's girlfriend and now wife.

Oops: "I burned down the entire office."

In my first high school coding job 14 I guess that made me a tech intern 14 I? burned down the entire office due to a cabling mistake. It was a total loss, displaced 100+ people, and destroyed lots of files, records, artwork, and a lot of the CEO's memorabilia. He never blamed me, but I think he knew it was my fault.

This intern switched off the Ukraine's banking infrastructure for 30 minutes by accident.

Image credit: Image Credit: Wikimedia Commons

It was my second year in university and I worked for a local ISP as a junior system administrator. We had a large wireless network ~60km in radius covering our whole city and many rural areas around it. This network was used by all major commercial banks and? many large enterprises in the area (~100 of bank branches, some large factories, radio stations, etc).

... When I wanted to shut down my local server I've switched to a terminal window that was connected to the box, typed "poweroff", pressed enter and only then realized that I did it on a wrong server. I had that second window opened ever since the monitoring alert an hour ago and now I've shut down the core router of our city-wide network.

We had to grab a car and drive to the central station to power the router back on, our whole banking infrastructure was down for 30+ min and that was one of the darkest days of my career.

This guy brought down the Washington Post for five hours.

I have to be anonymous.When I was interning at the Washington Post,I brought down the post's website for good 2 hours and publishing to the website for 5 hours.

While making a change in a very critical XML file,I forgot/was not aware that you have to escape the semicolon in the xml file.

However,my boss was cool and they didn't make a huge deal out of it.I eventually got hired at the Post also and gladly accepted the offer.

Fat finger: newbie deleted 80,000 lines of code with a single keystroke.

Image credit: Image Credit: Visual Density / Flickr, CC

I sat at the MySQL console for the production web application database and typed:

DELETE FROM tablename WHERE id - 1234;

...and hit return.

Note that I typed "id - 1234", not "id = 1234".

In MySQL the statement (value - value) is false if it evaluates to 0, and true if it evaluates to anything else. I just asked the database to delete all rows where the ID minus 1234 was not zero.

It replied "80,000 rows deleted".

This intern threatened to mutilate one of his company's customers.

(Person depicted is not the intern in question.)

Image credit: Image Credit: nanny snowflake/Flickr

This guy was an?intern product manager at NetApp.?To cut a very long story short, he was tasked with giving an important presentation to a client's chief security officer, who was determined to undermine his pitch.

The CSO demanded to know why his presentation didn't cover biometric security scanners, even though they were way beyond the scope of the pitch. The intern responded like this:

"So you want bio scanners with feedback right? That's cool. Well what's to stop me from cutting off your thumb and swiping it like in the movies? Nothing. Unless of course you want to integrate temperature and humidity monitors, and even then I'll defeat it by running tubes into your cut-off thumb with warm water or soak it salt water in the microwave-"

An intern at Facebook chose the username "www," with unfortunate consequences.

Image credit: Image Credit: Flickr/cybershotking

I joined at the beginning of my internship under the username www (they are my initials), and all the engineers' sandboxes started to redirect to mine because of the url address.

So yes, I managed to break things without even writing a single line of code.

This intern hit "reply all" at exactly the wrong moment ... "It was magical."

The CPA firm I worked for always hired 4 or 5 summer interns and they just got picked up to help on miscellaneous engagements as needed.? When they didn't have anything to work on, they were required to email the entire department with an "available for work" email so people would know they were free.

When one of the interns sent their email, another intern friend of his accidentally hit "reply all" with three simple words: Suck my d---.

The intern just told an entire department of 60-something people including partners, managers, department heads, etc. to "Suck it."

It was magical.? Everyone got the email at the same time and you could see heads start to come up over cube walls one by one like prairie dogs.? Managers slowly stepped out of their offices and everyone just stared at each other in shock.?

They now offer "reply all" training as part of intern orientation.

This intern unplugged his company's main server in order to charge his phone.

Image credit: Image Credit: Steve Kovach/Business Insider

This confession is brief, but you get the point:

"Plugging out the main server in order to plug in phone charger."

So this is why Facebook goes down ...

Image credit: Illustration: Ellis Hamburger

I brought down facebook messenger for nine minutes. Oops.

This big mouth accidentally persuaded his CEO to retire.

I got a CEO to retire. During one of my internships, I asked the CEO in a open-to-all meeting if he's doing his best to keep the company aligned with its mission and vision. He asked me who I was, thought for a few minutes [with about 200 people in the audience], walked out of the room, took a few more minutes, walked back in, and announced retirement.

More details about answer, since a lot of comments seem to be the same question:

+ This was not a mega mega company. It was a 500 people company.

+ The CEO was, afaik, not planning to retire. At the same time, there were already talks about the CEO being a possible candidate for getting fired soon as the company wasn't doing too well.

+ The CEO seemed to be in a state of slight depression; frankly, in his speech, he said that all he needed was someone to tell him where he lost it. And a question which most people did not ask [for not being on the CEO's let-go list], was asked by me.

This trainee sent a message to an entire company telling them their computers would run at half-speed for the day.

Image credit: Image Credit: Michael Philip Manheim / EPA (via Flickr)

I was 21 and at a multinational IT consulting firm. Target was one of our clients, and at that time, used the IBM dumb terminals for communication. The 'Message Send' command was used similar to IM now-a-days, but if you do not provide an id, it sent the message to ALL users (which few people knew about)

One Friday I sent, what I thought was a joke - 'To commemorate Blaise Pascal's birthday, all your computers will be run at half-speed today'. I thought it sent the message to all IT folks, but what I did not realize was that the message was sent to ALL uses - retail stores, Target business users, management teams etc. And that Friday turned out to be the 13th. So Target security thought it was a virus attack, and traced the origin of the message to, natually, my cubicle. I was called into work by my CTO at 2 AM, and I, with a pale face, explained how it was supposed to be a harmless prank. Then the CTO and with the CEO on the phone crafted an apology letter to the Target CEO/CIO with me right there. I was pretty sure I was fired, but I wasn't.

On the plus side I became famous and made lot of new friends in the company :). And Target implemented a change to the IBM send message to prevent this.

This guy was busted spying for the Chinese.

(Person depicted is not a Chinese spy.)

Image credit: Image Credit: REUTERS/Stringer

26 one day, the FBI swarmed down on our company. They came in fast and hard and all work came to a stop while we wondered what the hell was going on. It turned out that our intern had stolen the source code for our most precious and valuable techniques and tried to sell them to the Chinese for the pitiable sum of $50,000."

Unfortunately, the Chinese he was selling them to were undercover FBI agents. I never discovered how he set this sale up or how the FBI became involved, but here was a young man, not even a graduate of college, who was now heading off to prison for espionage, theft, and a dozen other charges, 26

A Microsoft intern was busted stealing Microsoft's new user interface for Microsoft Exchange.

Image credit: Image Credit: Paul Szoldra/BI

One day on week 3 into the internship our manager came in asking where my officemate was. I said I didn't know - probably at lunch. He said there was something going on with my officemate's PC... "security had alerted him". He didn't know anything else.

He walked over to my officemate's desk and hit a key, fully expecting the PC would be locked and he would have to wait for the guy to return. The computer was not locked. Right there on the desktop was the old-school Windows "flying folders" UI of files being copied from one drive to another.

The from drive: unreleased version of Outlook on Microsoft's internal beta fileshare.?
The to drive: some random external ftp server.

Needless to say the guy never came back from lunch.

At Amazon, this intern made the mistake of telling the PR team what he thought of them.

Image credit: Image Credit: Flickr/colindunn

The backstory here involves the infamous incident when Amazon began deleting copies of George Orwell's "1984" from the Kindles of owners who had bought a copy. (It was a badly handled publishing rights issue, but inevitably it caused headlines.)

An email thread blew up on which many Amazon staff contributed opinons critical of the way Amazon had handled the issue:

Since it was a giant sarcastic, idealistic cireclejerk, I decided to pitch in with a helpful and very common comment, calling the PR team "lazy" because they "didn't carry pagers" and were probably "not working hard enough" at solving this problem.

I subsequently realized I had the misfortune of being the very last person to comment on this thread. Suddenly, my snark was the most visible comment in a very unAmazonian (read: free opinion sharing)? thread.

Two minutes later I got a phone call..

"Is this <name retracted>? From that damn chatter thread?"
"Uhm.. yes.. who is this?"
"This is <name retracted>. Really? You really say shit like that? You really want to say shit like that? I'm the Vice President of Media Relations, it's seven PM, and I assure you, we are in fact working VERY HARD HERE. UNDERSTAND?"
"Uhmm, yes sir, I understand"
"KEEP THAT IN MIND NEXT TIME"
<click>

What not to do before you leave on Friday night: "I brought down 3 floors of AIG 19s Wall Street corporate network 13 for 3 days!"

Image credit: Image Credit: AP

I brought down 3 floors of AIG’s Wall Street corporate network 13 for 3 days! This is a true story.

26 New management wanted to bring in ATT/NCR servers running the then new Windows NT. ATT configured a server for us to test. They sent it to me on a Friday.

Before I left for the long weekend, I decided to plug it in put it under my desk.

... Little did I know that the server was a DHCP server. Put 2 DHCP servers on the same network and they’ll create a situation where all the clients get confused when they renew their leases. In a nutshell, my new server created so much traffic that nobody could use the network.

When I came in Tuesday morning, the CIO and several other big-wigs were hovering over my cube.? It was not a pleasant week!

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