I recall that the association / union boleto we received was meant exactly for joining a union of some sort. And you are absolutely correct: the minute you go

I recall that the association / union boleto we received was meant exactly for joining a union of some sort. And you are absolutely correct: the minute you go formal in Brazil, you become a target for all kinds of scams. I believe all data should be public in a democracy, but they should be public in a way that the person who queries it should identify somehow. That way they would know who downloaded the entire database and would have control of suspicious activity.