On a much smaller scale, I published a small change to a WordPress plugin I develop called Thank Me Later. Unfortunately, I had used a closure which was only su

On a much smaller scale, I published a small change to a WordPress plugin I develop called Thank Me Later. Unfortunately, I had used a closure which was only supported by PHP 5.3 and above. At the time, there were still a large number of users using WordPress with PHP 4.something. Being such a small change that couldn't possibly cause any harm, I got on the train and was away from the computer. An hour or so later, I opened my email inbox full of messages like "Help! My website is down", etc. I estimated I knocked at least 100 websites offline.