How cradled babe could be protesting? (2,2,4)

I believe the answer is:

up in arms

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'be protesting?' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for up in arms that I've seen before include "Protesting vigorously, ready for fight" , "being angry" , "held like a small child" , "Protesting strongly" , "Protesting vociferously" .)

I've seen this clue in the Sydney Morning Herald.

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