[andykmaguire]

This move is unethical for a very clear and straight forward reason. Demo Day at 500 Startups is "invite only". The YC company was not invited. People are invited for very targeted and strategic reasons. Information will get out, intentionally via press and investor conversations, but the timing is a critical factor.

The group is larger, but the logic is parallel to pretending to be an investor to hear a competitive startup pitch for capital, or sneaking into an internal team meeting at the competition.

It is a move without class.

[dhimes]

This is the right answer. Right now it's quite far down the page, so I hope OP sees it.

Think of it this way, OP: if there was nothing wrong with it, then the person doing it wouldn't mind being outed, right? So, out him or her and see what happens.