LJ Etiquette Question:

I'm not usually one to stand on formalities, but there are a couple of LJ etiquette questions that bother me.

Today's question: What is the etiquette for friending someone in a "Friending Meme"?

With the restart of 24, moosewizard put up a little 24 Friending Meme. goddess_loki has put them up for CSI:NY in the past. I love reading through all the answers, if just to see how different I am from the other fans. *grin*

However, how do they work, exactly? Does one just add an interesting person as a friend? Do you reply to the post and ask if it's okay to friend them or to ask them to friend you back? I've seen people do that -- ask permission or leave a note saying that you friended them. But then I see just as many replies that have no comments on them. Does that mean no one is interested?

Personally, I assume that people who reply to a friending meme are giving their tatic approval for anyone to add them. But I'm not sure that's what everyone thinks because I've see people who's journal is all "Friends only" and "People who don't think the same as I need not apply" when you go to their LJ.

I'm not up on the social niceties of LJ (obviously), so I'm relying on those of you out there who have a wide circle of friends: How does this work?