In the most hopeful scenario, some old lags might regard him in the same way they do "nonces", and devise some form of torment - maybe tying him to a chair while force-feeding him Bacon Frazzles and playing a continuous loop of an audiobook of The Satanic Verses on an iPod gaffer-taped to his head. For the next 25 years.
However, knowing our luck, while detained at the taxpayer's expense, he will find a ready audience of thick, disaffected young men seeking solace in the undifferentiated ego-mass of totalitarian religion, spread his poison and thus radicalise a whole new generation of murderous jihadis.
It is a pity he is a British citizen, otherwise we could deport him somewhere more to his liking - his beloved Islamic State, perhaps, and then to be bombed by the Russians and Iranians.