Can a Raspberry Pi be firmware updated?...I have a feeling from the suggested questions I'm being offered, the answer is yes.
I'm actually asking this from a security perspective, not because I actually want/need to myself. To explain, I'm wanting to leave a Raspberry Pi in what I'd guess I'd call a semi-public/communal place, without it's mini-SD card inside - alternatively I'm thinking of using a USB stick to boot/run the Pi and taking the USB stick away with me instead.
I'm confident enough that it wouldn't get stolen, but my concern is the lack of BIOS-style password protection on the Pi. My worry is the potential for a malicious/spying firmware being installed on the Pi without me knowing about it, as I may occasionally use the Pi for logging in to email and the like.
How big are my concerns on this? Bad idea? Is there any way I can make the Pi more secure?