I don't know if this is a bug or an intentional feature but if you opt out of getting anonymous questions, your profile page won't be reachable for anyone not logged in to RS. It shows an "Internal server error". TBH, I think of this as a feature and not a bug. It's like the "protect" feature of Twitter where only your followers can see your posts. I like the idea of my posts not showing up in any search engine results.