Government security agencies like the NSA can also have access to your devices through built-in back doors. This means that these security agencies can tune in to your phone calls, read your messages, capture pictures of you, stream videos of you, read your emails, steal your files … whenever they please.
Is Siri always listening? No. Apple says that Siri is not eavesdropping at all. The iPhone can only hold a small amount of audio, and it only records what happens after it is triggered by the “Hey, Siri” command.