One of the best responses to this I read on facebook.
A friend of mine Simon Bennet says:
“It is not too difficult to speculate about how this would pan out. The enforcement of UK immigration law, from raids and arrests, to detention, to enforced removals, is now almost exclusively carried out by private contractors. The catalogue of errors, physical, sexual, verbal, psychological and racist abuse, and very poor conditions of detention, show what happens when such an important function involving vulnerable people and authority/power relations is given to the private company that puts together the best bid. See the Medical Justice website for more info if you can stomach it.”