The answer to your question depend all on the country where the ICO or exchange is located. A court in the US recently decided that the exchange coinbase has to forward all customer data to the authority. In this case it does not rely on the amount and is like opening a bank account where your data will be submitted to authorities. US residents are currently anyway not allowed to participate in ICOs abroad. The US is doubtless the most regulated country in the world.
From what I've read regarding Coinbase, the IRS won a case and Coinbase has to hand in the identity of all of its users who withdrew $20,000 in US dollars.