For three years I worked at Bug Labs (open source hardware company). We not only told everyone what we did, we posted the source code and the blueprints online.

For three years I worked at Bug Labs (open source hardware company). We not only told everyone what we did, we posted the source code and the blueprints online. Nobody ever stole our ideas. Think about that, people won't even steal your ideas if you give them the plans. It would make a lot of sense for someone else to just come along and build our hardware and sell our software without paying for 15 people doing development and engineering, but nobody did that. Sure, we kept bits of information private like our negotiations with future partners or plans for the next version, but it really didn't matter that much. Now I work in the defense industry. What we do on a daily basis is a thousand times more secret than your "stealth" startup and we can still talk about it in more general terms than most "stealth" entrepreneurs talk about their project. So I call bullshit on the idea that anyone needs to keep a business idea stealthy, unless you are talking the nitty gritty details of the implementation's secret sauce, you will gain far more from sharing and making connections/partnerships than you will from secrecy.