George Clooney has no plans to sign up to microblogging website Twitter.com, because he fears one drunken tweet could end his career.

The Hollywood heavyweight admits he has never understood the appeal of social networking and the last thing he would want is fans bombarding him with comments all day and all night.

He tells Esquire magazine, "I don't understand why any famous person would ever be on Twitter. Why on God's green earth would you be on Twitter? Because first of all, the worst thing you can do is make yourself more available, right? Because you're going to be available to everybody.

"So one drunken night, you come home and you've had two too many drinks and you're watching Tv and somebody p**ses 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."

Referring to one specific tweet which caused a storm of controversy online, he adds, "I mean, when you see, like, Ashton Kutcher coming out going, you know, 'Everybody leave Joe Paterno alone,' or whatever he said, you just go, 'Fifteen minutes longer and a thought process and probably you wouldn't have done that.'"

Kutcher came under fire in 2011 after slamming education officials for sacking the Pennsylvania State University football team head coach amid allegations he failed to take action against assistant Jerry Sandusky, who had been charged with molesting young boys over a 15-year period.

The actor apologised for the irresponsible tweet and removed himself from Twitter, before reinstating his account and handing control of his profile over to his management team.