By now, nearly everybody knows the back story of Facebook. Mark Zuckerberg and some friends hacked into the computer system at Harvard University and started a website to compare pairs of incoming freshmen. Then, he created a social network that was only for college students, and it took off like wildfire. Now, everyone can use Facebook, and it has become one of the biggest websites in the world, with the company being worth billions of dollars. For many people, Zuckerberg is a shining example of ingenuity. He came up with an idea that he still keeps improving to meet consumer demands.
　　Facebook has only been around for 10 years, but in that time, it has had more than one billion people sign up for its service. To show how huge it is, if Facebook were a country, it would be the third largest in the world behind China and India in terms of population.
　　Think about it. Are any of your friends not on Facebook? Wouldn't it be weird if they weren't? Nowadays, nearly everyone spends a few hours each day using its various functions. These include users checking their mail, writing status updates, sharing pictures, and looking through their newsfeeds on Facebook.