If you're just at the "idea stage", then no one is going to steal your idea.
If you've progressed further and have some traction, some lessons learned in customer acquisition channels, etc., then you should be cautious about what you share because your information has real value.
If you've progressed further and have some traction, some lessons learned in customer acquisition channels, etc., then you should be cautious about what you share because your information has real value.