True that physical possession lowers the risk barrier considerably, but still this threat is problematic in a couple of ways. a) An unattended laptop can be co

True that physical possession lowers the risk barrier considerably, but still this threat is problematic in a couple of ways. a) An unattended laptop can be compromised in under five mins, all without any obvious indications. There are also loaner situations, at schools etc. where machines are shared. b) no specialized hardware is necessary, so it's really cheap to execute. c) this is probably the worst part - power cycling the laptop does not reset the T2 ("The T2 chip is fully booted and stays on, even if your Mac device is shutdown.") - so there's no practical way to ensure that your machine is not compromised after a brief interlude. For extra fun, if it turns out the attack can be executed by a malicious wall port, then things start to get really interesting.