Every additional data source makes it easier to collect the data; the vigilance needed to monitor access to one source is hard enough, but it scales poorly with

Every additional data source makes it easier to collect the data; the vigilance needed to monitor access to one source is hard enough, but it scales poorly with additional sources. It's why we tolerate so much incursion into our privacy: the effort necessary to operate anywhere near "normal" and maintain data privacy is almost insurmountably difficult.