It's not just email address, I listed all required data for token sale sign up, none of them are optional. The required personal details are marked with an asterisk, they are:
They specified that they will share data with advertisers and affiliates, current or future, and also upon government request, in addition to legal demand be it legislative or regulatory.
It's a matter of user discretion, I chose non participation, and thought I would share my reasons here. To each their own.
RE: DTUBE COIN SALE ROUND #1 is live !