The problem with using the Corporations favourite dodge, 'the diffusion of responsibility', along with homeless people is that they have not been sufficiently indoctrinated to the cause and so the drum of rhetoric will not be tight and loud.
Using such a dodge in the real world, where they don't have full control over their 'employees', is sure to generate some kind of organised retaliation by the community.
Allowing the host to create antibodies is generally considered to be a bad move for parasites.
Perhaps they can minimise their culpability footprint by forcing the homeless people to sign off on some kind of 'Unfairness Awareness Training' program. A multiple choice, Flash based, click-through quiz which educates them about their status as chattel-property and forces them to sign away their rights before being allowed to complete the compulsory 'training'.