This is what happens when you expect people to work for you for free.
i'm not sure why everyone gets in a twist over free interships -- nobody's forcing you to participate. if everybody thought it was a rip-off, nobody would apply, and employers would be forced to pay the interns.
the fact is that the competition for an internship is so intense, that TC is giving a net benefit to the person who works there, even though they aren't getting paid monetarily.