Seven tips to secure your iPhone from hackers
1) Use a PIN or fingerprint security
2) Or use a longer passphrase
3) Self destruct
4) Privacy settings
5) Turn off notifications
6) Disable Siri
7) Type it yourself
If you're serious about stopping intruders then you can tell your phone to delete all data if it thinks someone is trying to break in. Under the same page on settings you can enable "erase data" - this will wipe the phone clean after ten incorrect guesses at the PIN. If you have Touch ID enabled then it will allow you three chances to get your fingerprint recognised, then it will revert to PIN entry.