Ok, so it's not 100% private. But still, no one knows who you've contributed to, and how much. Heck, no one even knows whether you've contributed anything at al

Ok, so it's not 100% private. But still, no one knows who you've contributed to, and how much. Heck, no one even knows whether you've contributed anything at all; maybe you just ran your washing machine. As far as passing money between people goes, it's more private than giving someone cash in a back alley.