Hey sorry about that, it's been a while ago, we didn't know that emails on Github were not allowed to be used (since I received many emails from startups that way). We apologized to our users and never did this again
I don't know anything about this company and what it may or may not have done, but to be clear, the link just says that when you star their github repo, they add your email address to their marketing list.
I think that sucks, but it's certainly not what I thought of when I read your one-liner (which implies that they harvest and abuse your actual recorded data).