Going to a party uninvited always has been a negative action. It never has been acceptable. At the very least, it upsets kitchen preparations, parking arrangements, and even details such as space for hanging coats and depositing dripping umbrellas.

Facebook has gone from a nice-and-boring social network to becoming an identity layer of the web. It is where nearly a billion people are depositing the artifacts of civilization in the 21st century - photos, videos, and birthday wishes.