A news article recently published by Al Jazeera editors claimed prisoner Abu Zubaydah had been forced to listen to one of the group's songs on loop at high volume for long periods of time as a form of torture.
Drummer Smith admits he had no idea federal officers had been blasting the band's tracks at the controversial detention centre for suspected terrorists and insists he is appalled by the idea.
He tells Tmz.com, "I've heard that they use more... like, hard rock, metal... (but not Red Hot Chili Peppers songs).
"Our music's positive man, it's supposed to make people feel good and that's... it's very upsetting to me, I don't like that at all. It's bulls**t.
"Maybe some people think our music's annoying, I don't care, but you know... (they) shouldn't do that. They shouldn't be doing any of that s**t (torture)."
The Give It Away hitmaker isn't the only musician to take issue with the use of the group's work at Guantanamo - heavy metal stars Metallica previously voiced their objections to the same practice.