23 Things Number 9

Speaking of Facebook friends, I accidentally confirmed someone as a friend who I really did not want to have contact with and that was a little traumatic (I have a yoga student with a very similar name and thought it was her). I have also had friend requests from various people I don't know or whom I barely know. I don't really understand "friending" someone you weren't ever friends with. I feel rather rude ignoring them, though, so it always leaves me in an awkward predicament. What is the web etiquette for that situation, exactly?