One way to think about the Internet is that there are two of them. There's the public one that we share with our co-workers, friends, and family. There's also a more furtive, creepy one where people exchange porn, shock photos, and other, darker droppings of human endeavor. The 2 Girls 1 Cup video originates from this shady side of the Internet. As you may suspect, it involves girls and a cup. I haven't watched it. (No thanks.) But I have watched a lot of other people watch it. For the past few months, teenagers, college students, and office mates have been screening the video, recording the responses, and posting them on YouTube. The result: the 2 Girls 1 Cup reaction video, a rare instance of the public Internet converging with the disturbing Internet. (The actual 2 Girls 1 Cup video is not seen in any of the reaction videos we're posting.)