Eliezer Yudkowsky comments on Quixey Challenge—Fix a bug in 1 minute, win $100. Refer a winner, win $50.

[Eliezer Yudkowsky]

They are posting by invitation.

[Clippy]

So a social engineering attack, then. Very devious—the attack shows they could very well program an AI that can convince a human to let it out of its sandbox!