So, let me get this straight: you are advocating that white hat hackers download data in bulk to determine whether or not there is a breach of privacy? Do you realize that at that point in time there is a breach?
I'm really more than a little bit surprised that people here don't seem to know the difference between reporting a vulnerability, which has the potential of being exploited and actually exploiting it.
> download data in bulk
This phrase is doing a lot of lifting here. Op clearly downloaded far less than is possible.
> Do you realize that at that point in time there is a breach?
As others have said elsewhere, this is a legal opinion and IANAL. Morally: downloading data, not reading it, then deleting it, then reporting it does not strike me as unethical.