That really depends on the details of what's capable with their collection equipment. Transoceanic cables are obvious, but there are also satellite-satellite l

That really depends on the details of what's capable with their collection equipment. Transoceanic cables are obvious, but there are also satellite-satellite links that are possible that could terminate right in Iowa for all we know, that the NSA wouldn't be able to retain unless/until it made it to one of the Tier 1 ISPs (they might use geolocated IPs for this). And as the other comment mentions, the minimization procedures seem arranged to blacklist and discard only that data which is clearly US<->US so you could definitely end up with your data being socked away.