Re: Good on them
... and this is the job of the state: ensuring everyone plays by the rules.
When economists preach that competition is a good thing, Joe Average should safely be able to hire the cheapest cab, since it is not his role to safeguard working conditions for the cabby are adequate.
This is the role of the government, to set the rules, and to enforce them.
Naturally, some grey or black offerings will work-around the rules, but that is the definition of a grey or black offering: partially or totally being against the established rules.
If we want our market economy not to adopt modern equivalents of slave labour, we need to make sure we do not dismantle the state, who is the only entity to force companies to stick to the rules.
A public call for boycot is nice, yet the spectre of jail for managers of said companies is generally a stronger incentive to play nice and fair.