Cancellation of Protection Visas

Should Australia be cancelling the visas of persons who are owed protection under Australia’s international treaty obligations?
Is it enough that Australia punish people who are convicted of criminal offences while holding protection visas, or should they be “sent back” to the countries of their nationality notwithstanding that they would be at risk of harm?
How should the balance be struck between the very legitimate interest in protecting the Australian community from the risk of harm associated with releasing a person with a serious criminal history, and, on the other hand, Australia’s “non-refoulement” obligations?
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