Indeed. I would argue that the free market, itself, carries no inherent morals. The morals, instead, lie within the consumers, and businesses. If the consumers are opposed to slavery, then, on moral grounds, it would be expected that they would boycott such a business. As such, a business would be inclined to not use such forms of labour since the public wouldn't give them their business; however, it seems that the populace doesn't care too much about those under the employ of a company as evidenced the rampant use of child labour, sweatshops, and poor human rights conditions by major corporations with foreign manufacturing -- if the public is not opposed to such forms of obviously cheaper labour, then the market will certainly make use of them.