Don't know, I didn't try what happens when a field is left empty, but the text near each field (Username, Email, Password, Date of birth, Location, not a bot Verification) reads "Required".
Found the other settings in the profile, thank you.
Don't know about the law, might be, I don't care, I was asking only out of curiosity, but I wouldn't be surprise if there are indeed such laws. For example, we still have some stupid law here, in EU, to enforce any website (even if from outside EU) to request user informing, and user's explicit acknowledge for receiving cookies.
The effect of that law was that now each website pop-up various info + questions, and require ticking check boxes and making various categories selection before access, so everybody is using uBlock or other methods to avoid the cookie permissions dialogues. Many don't even know what is all that cookie nonsense about, and select whatever while cursing, and some websites outside EU simply didn't bother, and just denies access to any EU visitor.
