There appears to be a bit of a conflict between the cardinal rule you were taught when you worked at NSA of not collecting information on US persons with the current practices of the NSA.
The Section 215 program in which the NSA has been collecting metadata about every domestic telephone call would appear to violate that rule, even if, as we are told, only a couple dozen NSA employees can query the database, and even if they only use it for investigations related to terrorism.
Likewise, the non-us persons targeting rules leaked last week suggest that the NSA has ongoing access to GSM Home Location Register data for the entire United States. While this doesn't pinpoint someone's location to a house or street, we're still talking about the NSA getting city-level location data for hundreds of millions of innocent Americans.
See page 6 of:
http://www.guardian.co.uk/world/interactive/2013/jun/20/exhi...
Given how compartmentalized NSA is, it seems quite reasonable that your former team (which, I assume, penetrated the computers of foreign targets) would have no contact at all with the teams tasked with collecting domestic communications.