Unless you are not installing ANYTHING on either, privacy or security on either doesn't really exist. As apps are one of the big offenders. Another thing people seem to not understand is that Apple also sells user data like Android, it has been reported many times that the data set collected is one of the richest in the industry. Now, like Android, they claim it is all scrubbed of personal identification etc etc, how much of that you believe, or how secure the methods that are used for this and if they are not back traceable in some form, is highly debatable, but a few researches have been able to narrow down the data to specific people fairly accurately with the scrubbed data collected from both. And all of that assumes no backdoors built in that none of us will probably never know for sure if they exist.