The issues are as follows. Is the purpose legitimate? For example, I'm suggesting that tracking fraudsters is now accepted as legitimate. Do people know about it--unless, of course, it's a national security issue; that may be something different. Do they expect it? Do they have access rights? If I find that I've been wrongly data-matched with somebody else, somebody who has a similar name and so on, what can I do to contest this?
I suggest there is now very limited recourse for citizens in the act. But you've worked on data matching--