[falcolas]

Semantics. If you're working in Facebook's offices for a large majority of your hours, you're effectively working for Facebook. They've just added the middle man to avoid paying decent wages.

Your HVAC worker who may spend 4 hours a month on the Facebook campus is different from someone whose daily job is to clean Facebook's headquarters.

[tyingq]

Building Maintenance and HVAC techs spend a lot more than four hours a month on the campus they support. Or landscaping businesses for example. Or security guards.

I just don't see how the building that you work in defines who your employer is. There's lots of counterexamples for that.

If I own a business, and don't want to have expertise, training, etc, in food service, laundry, security guards, landscaping, etc...I should be able to get a company to do that for me. That company has expertise in hiring, training, regulatory compliance, etc. They are delivering that service to many companies, not just me. Their employees might even be transferred from one client to another. They charge me whatever the going rate for that sort of thing is. They then pay their employees however they do. If they are underpaying their employees, that's an issue, but not one that's my issue to solve. That is, barring some odd thing where my company, specifically, is using some unusual kind of leverage to NOT pay market rates for this service. I see no difference in whether that service happens on my campus or somewhere else.

[echaozh]

Employment is not thus defined. If I am a salesman responsible for 1 particularly important client for my company and spend almost all my time at the client's office, am I suddenly the client's employee, and they should pay me decent wages?