Earlier quoted context omitted.
Do they have actual terms of service by now? When I tried it, I was signed up to their newsletter by simply entering a mail address into the account setup dialog, without any indication that I was opting in to have my personal data harvested and abused.
There was a (really bad) bug in one of our releases that did this. You must have connected then-- sorry. We're a small team moving fast and occasionally we screw up like this. FWIW, it now correctly asks you in the setup flow and you can add/remove yourself in the preferences: https://i7.createsend1.com/ei/d/A1/835/432/153754/csfinal/pr...
You might want to think over how you communicate with your customers. Customer privacy isn't something you can just shrug away.