I was loitering around Coolidge Corner today. There is a very nice bookstore there, Brookline Booksmith, and they also have an interesting calendar of events. On Thursday, Jan.13, 7pm there will be a meeting with Gabriel Jeffrey who runs a popular Web site for making and reading anonymous confessions, grouphug.us, and compiled a book out of them called Stoned, Naked, and Looking in My Neighbor's Window.
There is also a brief Wikipedia article about them. Besides voyeuristic value, this seems to be an interesting phenomenon to look at.