While pop stars and reality show notables are among the most popular users on Twitter, movie stars have, for the most part, resisted the impulse to join the social networking fray. And though more and more are making the leap into the land of hashtags and @-replies (both Cameron Diaz and Sarah Jessica Parker signed up last week), there is still a large contingent that shuns the tool. This past week, long profiles of George Clooney (in Esquire) and Julia Roberts (in Marie Claire) touched on their aversion to Twitter, George going so far as declaring he doesn’t “understand why any famous person would ever be on Twitter.”

So what are the various reasons these A-lister hold-outs give for rejecting the service?

All people tweet about is what they’re eating for lunch.

Daniel Craig: “I am bloody not [on Facebook]. And I'm not on Twitter either . . . ‘Woke up this morning, had an egg’? What relevance is that to anyone? Social networking? Just call each other up and go to the pub and have a drink.”

Tina Fey: “Most people are so f-----g boring that they should shut up, and you should have to get a license. And I'm volunteering to be in charge of the licenses . . . Go write it in a journal and mail it to your grandma.”

They want their privacy.

Sandra Bullock: “[I’m not on Twitter because] I don’t want anyone to know where I am.”

Using it can leave you feeling gross, one way or another.

George Clooney: “So one drunken night, you come home and you’ve had two too many drinks and you’re watching TV and somebody pisses you off, and you go ‘Ehhhhh’ and fight back. And you go to sleep, and you wake up in the morning and your career is over. Or you’re an a--hole. Or all the things you might think in the quiet of your drunken evening are suddenly blasted around the entire world before you wake up.”

Julia Roberts: “[Social media] is kind of like cotton candy . . . It looks so appealing and you just can’t resist getting in there, and then you just end up with sticky fingers and it lasted an instant.”

For some, personal vendettas seem to be at play.

Kristen Stewart: “Twitter f---s me over every day of my life. Because people go, ‘I’m sitting next to Kristen Stewart right now’ and then [the paparazzi] show up.”

Others just find the idea of it overwhelming.

Jennifer Lawrence: “Everybody was talking yesterday about Twitter and Instagram and Tumblr. It was really confusing me and overwhelming me. I literally started losing my breath. People were showing me these hilarious things and I was like—I want to have this. What’s Pinterest? I don’t have it. I know by the time I get it, it’ll be something else. I bought a CD case less than a year ago.”

Some have high-minded objections related to “art” or whatever.

Bradley Cooper: “For me, maybe I'm old fashioned, if I know so much about you and you’re playing a character in a movie then that’s a lot of work I’m gonna have to do to forget who you are so that I can believe the character and therefore enjoy the movie.”

Chris Hemsworth: “I think there’s a danger of being overexposed with that stuff. The mystery of who you are is what keeps people interested in wanting to see you on the screen. Also, it’s easier for them to believe you as that character if they don’t know too much about you. It’s hard not to be overexposed these days with the Internet.”