ATF can't be trusted with the information they have NOW,

and they want to be given more?
The U.S. Government Accountability Office (GAO), the go-to federal oversight agency, conducted an audit of ATF and found it does not remove certain identifiable information, despite the law explicitly mandating it do so. GAO conducted reviews for four data systems, and concluded at least two of ATF’s systems violated official protocols.
And anyone who's surprised either hasn't been paying attention, or is a fool.

You might remember that the head of BATFE announced a few days ago
What he would really like, however, is a computerized database of all gun purchases made by every buyer and seller in the country:

There’s a lot of things that don’t make sense.… Would [having such a database at the ATF] be efficient and effective? Absolutely. Would the taxpayers benefit with [improved] public safety? Absolutely. Are we allowed to do it? No.

What he doesn't mention is that they're forbidden to (legally) do so because the agency has proven it cannot be trusted to obey the law, and not abuse such information.  Now read this from the GAO post:
Accumulating and centralizing such data can become harder to maintain as time goes on. GAO recommends that ATF eliminate or at minimum obfuscate the unnecessary data to comply with federal law and to ensure that unnecessary information isn’t vulnerable to breaches or internal infractions.
ATF can't- or won't- obey the law on what they've got now; the list the ATF head wants would multiply the data by God-knows-how-many times, and we're supposed to believe they'd obey those laws then?  This would wind up like the NFA database, which is incomplete and can't be trusted to be accurate, yet there are recordings of supervisors telling agents that if asked, in court and under oath, they should testify that it's complete and accurate.