Miley Cyrus -- Smilers Turn Up Heat On Patrick Schwarzenegger for Spring Break Pics (TMZ TV)

Miley Cyrus’ fans are so savagely loyal -- they're actually threatening Patrick Schwarzenegger after he was photographed doing body shots off a female “friend” in Cabo.

Just because they're called “Smilers,” doesn't mean they can't challenge other celeb fan clubs ... in the crazy department.