Hacker from Chiba seen in court action (4)

I believe the answer is:

case

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'court action' is the definition.
(as in a court case)

I don't understand how the remainder of the clue works.

(Other definitions for case that I've seen before include "that paperback lacks?" , "baggage item" , "Cover" , "Judge tries this" , "Carefully inspect < suit" .)

I've seen this clue in The Times.

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