Comment by wry_durian

It can very much so be a data breach for government to "have access to" other agencies' data. Check whether U.S.C. § 3552(b)(2) contains any exceptions or carve-outs for government agencies!

One of the main points of privacy legislation is to functionally limit the government's ability to collect, use, disclose, and retain personal information in the first place. That's entirely contrary to the idea that government departments can share or access it pell-mell.