In the Matrix movie (1999) as well as in the Matrix screenplay (Rev. 3/9/98) Morpheus calls Neo and the first sentence that comes out of his mouth is:
This line is tapped, so I must be brief.
Later he proceeds saying:
MORPHEUS (V.O.): They got to you first, but they've underestimated how important you are. If they knew what I know, you would probably be dead.
NEO: What are you talking about? What the hell is happening to me?
MORPHEUS (V.O.): You're the One, Neo. ..
I was always puzzled by this ever since I saw the movie way back and recently when I read the screenplay. Morpheus confirms that Neo's life would be at stake if the enemy knew what he knows.
Why does Morpheus tell Neo he is the one over a tapped line?