When you connect a bunch of young college kids together on the Internet, any meeting eventually devolves into a crying mess of memes, Internet hall of fame pictures and a whole lot of trolling. So when students in Stanford's computer science program realized that e-mailing one address would contact EVERY student, well, you bet it got real fun real fast. People were dropping tubgirl, rickrolls, meatspin and because it's Stanford and it's computer science, offering jobs at startups.
This happened recently when 40,000 students at NYU realized they could exploit an old ListManager program and e-mail all 40,000 students at NYU. Stanford's mistake was arguably even easier access: ANYONE can e-mail ANYTHING to EVERY computer science Stanford student at this e-mail address: email@example.com.