During a visit to the human world, Princess Twilight Sparkle was taught some of the basics of how the internet works by her human counterpart. She planned to have a field day surfing the web to learn more about her human friends' world.
However, thanks to luck and previous activities, Princess Twilight was led to a "mature" website. Being born a pony and raised in Equestria, she didn't understand the true gravity of what she was seeing. Worse, none of that boded well for the human Twilight...