Users have contributed to some of the worst cyber attacks that have happened in the world. For instance, the worst attack on Yahoo, an email service provider, was caused by just one click from a user. The FBI investigated the cause of the breach that led to the compromise of millions of user accounts and discovered that there were spear-phishing emails that were targeted at specific Yahoo employees. It is said that one of those targeted clicked on a malicious link that led to hackers compromising the employee's computer and using it to gain access to the network.
Once in the network, the hackers installed a backdoor that allowed them to connect to and steal Yahoo's user database. Investigations revealed that the hacker responsible for these operations handed over the stolen database to other commercial hackers. Soon, the hackers started...