If by 'Apple' you mean 'AT&T' and by 'let you do it' you mean 'give you a direct line from your data center to AT&T subscriber location data with which you can approximate the feature with the Push API and no actual third party code running in the background on each phone', then I concur with your assessment.
http://www.businessinsider.com/loopt-to-run-in-the-backgroun...
I guess if you fellate / pay Apple enough, they let you do it.