DigiNotar

Diginotar was a company that made something called digital certificates that helped make sure websites were safe to use. When you go to a website, your computer checks the digital certificate to make sure the website is really who it says it is and not an imposter trying to steal your information. Diginotar messed up by allowing bad guys to hack into their system and create fake digital certificates, which they used to trick people into going to fake websites that looked real. This was very bad because people who went to those fake websites could have their personal information stolen. Diginotar eventually went out of business because they couldn't keep people safe anymore.