A Wide Diversity of Consumer Attitudes about Online Privacy shows this picture of Flickr users setting privacy preferences: green is public (default) and red is private.
I hope Flickr shares some of the underlying data. I don’t know what anyone would do with it, and there’s two ways to find out. One is to talk, the other is to release the data. (For privacy reasons, coded to a broad anonymity set, like the zip code in the US, or groups of postal codes elsewhere.)