securing your imac w/silicon from physical intruders

Apple Silicon Macs do not have firmware passwords.

You should start by doing at least three things:

• Disable the Guest account
• Use a strong password for your user account(s) and keep it(them) secret
• Shut down your Mac when you are away from it.

Also, on Apple Silicon Macs, the default security configuration only allows booting from the SSV, so an attacker could not boot from an external drive to access your system (it just wouldn't boot).

Apple advises enabling File Vault to protect your data but that alone does not block someone from starting up your Mac.

Use a Touch-ID keyboard.

Apple Silicon Macs (and Intel Macs with T2 chips) encrypt the contents of their internal SSD in real time.

If you have any of these Macs, you better have a backup, because if the machine suffers a hardware failure, you're not going to be able to pull the internal drive out to recover data off of it. Even if the flash chips aren't soldered in (which they probably will be),

• The modules probably won't be standard M.2 SSD modules – just "raw flash" modules.
• Most or all of the contents of the flash modules will be encrypted with a key stored in the Apple Silicon SoC (or the T2 chip). If you put the flash modules into an external enclosure and try to use them with another machine, that machine won't have the encryption/decryption keys to decode their contents.

Even with Touch ID activated, one can still get into the computer using the password.