facebook, myspace, twitter

So it looks like there are these three mainstream social websites. Which are you using and why? What are the advantages and disadvantages of each of them?

I heard many people complaining about facebook privacy settings, but actually, I've never had problems with them. You just go to privacy settings and control who can see your profile and how. For example, I have a list of friends, who can see everything about me. Friends of friends can see some limited information, while everybody else can see nothing! Literally nothing. Non, zip, zero, nada. Also I have a list called "invisibility". Why? Did you ever get a friend request from someone who you don't know? Well, I don't refuse these requests, but I put all these people into this invisibility list. What can they see about me? Literally nothing. Non, zip, zero, nada. What can I see about them? Everything!

I personally don't like twitter, and I heard youg people saying about our generation: "why would they invent twitter? It's so stupid!"...

myspace - never used it... it looks like everyone can register. On facebook it is good that you can enter the network of your school or work onl if oyu have the corresponding email address. But now much more people can join too - and this leads to fraud, spam and quality loss. But it looks like they're working hard to fix these...

Also good network is linkedin - but that one is purely professional. Do you know of any hires which were initiated on linkedin?