Such exploits cant be viewed lightly (4,5)

I believe the answer is:

dark deeds

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'cant be viewed lightly' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'such exploits' is the wordplay.
'such' becomes 'dark' (I can't explain this - if you can you should give a lot more credence to this answer).
'exploits' becomes 'deeds' ('deed' can be a synonym of 'exploit').
'dark'+'deeds'='DARK DEEDS'

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I've seen this clue in The Irish Independent.

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