I am an entrepreneur in San Francisco and am afraid to tell people about my business idea without ensuring that I'm legally protected first.
Lawyers will tell you they can protect your idea, but the truth is that unless you have a lot of money to follow with a lawsuit, most protection doesn't do much. Copyright is a slow and lengthy process.
I remember 2 tech entrepreneurs in Poland who got introduced to the head of a big Polish bank by a friend of mine. After the meeting the head of this bank called my friend and said "they were lovely people but why did you send them to me?". When my friend called the 2 tech entrepreneurs, they told him they didn't share their idea because they were worried the head of the bank would steal it. They never got another meeting with the head of this bank who was initially interested in giving them funding, and my friend never made any other introductions.
From experience coaching and consulting for a lot of tech start-ups, the best way is to build a strong brand and to make the most of your first mover's advantage. In terms of privacy, you can get people to sign Non Disclosure Agreements and share your idea only with people you have build relations and trust with.
You can schedule a call to find out how to make the most of your first mover's advantage.