Khalid Shaikh helped create the file-uploading company YouSendIt. After battling with the CEO, he was fired—and he soon launched a series of cyberattacks:

“In Shaikh’s absence, YouSendIt had continued to grow. It had raised an additional $14 million in VC funding and had 100,000 paying subscribers. Still, Shaikh marveled at how often YouSendIt’s site went down. He had even sent a tip about one of the outages to Valleywag, an industry gossip blog, which ignored his e-mail. If YouSendIt’s servers were still running the way he had left them, he believed, the site wouldn’t be crashing. At YouSendIt, Shaikh had been the subject of what he calls ‘senseless, mindless pressure’ to keep the servers running. Now, no one seemed to care.

“So, on a chilly Tuesday morning in December, Shaikh ran a piece of testing software, called ApacheBench, that flooded YouSendIt’s servers with traffic. The servers keeled over immediately. Later that day, a sentence appeared on YouSendIt’s Wikipedia page: ‘Looks like the company may be out of business, their site is down.’”