Oh, for crying out loud.
This is the passage s/he's referring to, from James 3, which has a long section about using words in a loving way:
"With the tongue we praise our Lord and Father, and with it we curse men, who have been made in God's likeness. Out of the same mouth come praise and cursing. My brothers, this should not be."
James is writing to Christians (surely no one would dispute that), exhorting them to cut down on the amount of vicious speech they're doing because it really isn't in keeping with the ideals they claim. It has nothing to do with the use of English "curse words."
I haven't heard Bono curse much of anybody in that sense ever.
In a wider sense, since I suspect anyone who would be in an environment that would pick verses out of the Bible out of context that way would claim to believe that accepting Christ by faith is the be-all and end-all of Christianity, I would ask the person, "so for you then what makes someone a Christian isn't faith in Christ, but following a law code of behavior?" and see how they responded.
If s/he is interested in U2, pass along a copy of _Walk On_ == Stockman answers this kind of malarkey beautifully.
