I only use Facebook and Twitter, so I chose against them. I used to use MySpace, but that got to be a pain (worse than Facebook), so I dropped it. I've never heard of "Orkut".

I hate that FB uses that "neverending page" code. I'll be scrolling, it'll stop, and then load a bunch more posts and lose my place. I know I'm part of the problem, because I've added so many friends and "Likes" that I'm constantly barraged with content, but I get frustrated trying to keep up. I can't even check my responses from other people in threads I commented in, because I lose track. There's also a technical glitch that sometimes happens where it won't let me "Like" something--it turns to "Unlike" and then right back to Like. (I've found re-sorting the posts to "Most Recent" fixes this issue.)

I'll mention Twitter briefly, too. Most of the posts are short, unhelpful words that don't really explain the inevitable link that accompanies them. I just want the message, I don't want to click a link to see a picture or a longer post somewhere, because when I'm done with that, I'll have to go back to Twitter and scroll to the next message I want to read, click that link, then read the text and/or view the photo/video, then back to Twitter...Grrrr! I just want to scroll down through Twitter and read each message (which should be SHORT and to the point) until I want to stop. I hate all these extra steps you have to take. FB allows links, too, but at least you can include a paragraph to explain what the link is, so I'm less likely to waste my time.