Is it necessary / recommended for your investors and advisors to sign an NDA before you can share confidential info with them? It seems many NDAs from brokers technically allow this, but still hold you responsible for any breaches - which makes it a bit of a grey area.

Would be interested to hear how searchers have handled this - for both informal disclosures (e.g. phone calls, emails) and formal ones (e.g. Confidential Financing Memorandums).