Open your iPhone. Settings -> Touch ID & Passcode. (The red fingerprint icon) -> scroll all the way down and TURN OFF "USB accessories".
Remember the longer your passcode (longer than 15 characters)the better chance of your device surviving brute Force attempts. https://twitter.com/sa0un/status/1127939051015802880
Ceejbot's mastodon instance. This is an overprovisioned, personally-run instance running on AWS. I welcome friends to create accounts here. I intend to run it as long as people are using it.