As I see it, TLDR is: we needed a lot of people, cheap, and mega-contractor-shops is the only way to get the headcount, cheap. We also wrote nice contracts that

As I see it, TLDR is: we needed a lot of people, cheap, and mega-contractor-shops is the only way to get the headcount, cheap. We also wrote nice contracts that require them to treat workers well, so if they don't, it's clearly not our fault. Also, we hired somebody who will be responsible for dealing with such things. So everything is going fine, except rare exceptions which we take very seriously. Thank you for providing feedback, it was very valuable for us.