Celebrities are all getting together for another good cause!

Lady Gaga, Justin Timberlake, Ryan Seacrest, Usher, Kim and Khloe Kardashian - the list goes on and on - have all joined a new campaign called Digital Life Sacrifice on behalf of Alicia Keys' charity Keep a Child Alive.

This Wednesday, which is World AIDS Day, these celebs will sign off social networking sites like Twitter and Facebook until the charity itself raises $1 million.

"This is such a direct and instantly emotional way and a little sarcastic, you know, of a way to get people to pay attention," said Keys.

And president of Keep a Child Alive Leigh Blake believes that "Gaga is going to raise it all by herself."

Good luck to everyone!