Alan is a huge Samsung fan but keeps hearing that iPhones are more secure. Is that true? Leo says that they're both very secure, though Android phones are encrypted at the software level, while iPhones use a hardware secure enclave to keep encryption keys. Apple's iTunes store is more secure than the Play store only because it has a tougher standard for approving apps. But if the Pentagon approves Android phones for use, that is a pretty good seal of approval. Having said that, users can "sideload" third-party apps if they turn off the security feature. But at the end of the day, both are very secure. Even then, some things get by both of them.
Check out Privacy.io for information on how much of one's data is private and how much is available for public consumption.