In the letter (available here), Bruce Sewell, general counsel and senior vice president of legal and government affairs at Apple, details answers given by Markey which were subsequently published by Apple.
As one of the biggest privacy stories of the year, it sparked a wide-ranging debate about location based privacy and what our phones collect about us without the users' direct knowledge.
But there are questions that still remain to be answered.
1. How will Apple encrypt location based data?
Will it be in such a way that Apple holds the encryption keys, and if requested by law enforcement can decrypt that information, or will it be encrypted 'automagically' based on the unique properties of the device? I suppose it would be the former and not the latter, as the data needs to be sent back to Apple to be read.
But it does make me wonder whether encrypting the location data on the handset will do any good. Sure, it means that anyone who steals your phone won't be able to find out where you've been, but not much good otherwise.
2. Who is the third party involved in sharing "subsets of the anonymous location"?
Apple cites "non-disclosure restrictions" and "contractual confidentiality" to protect the anonymous location information from being shared with others beyond this development partner, but it does not explain which information is passed on.
But if Congress wants to know more details on this sharing arrangement, then so should the wider public.
3. If users had their data collected by Apple even when they turned it off, will users be told (or Apple investigated)?
It'd be funny if they did tell individual users that they had their locations collected even when they had turned it off -- whether it was a result of a bug or otherwise -- because then it would prove that individuals could be identified by Apple.
Probably won't happen though. But even though the Federal Trade Commission made it clear that it "didn't comment on individual cases", perhaps only time will tell if Apple will be investigated by the authorities for any number of reasons relating to the location tracking scandal.