I see. It makes sense, and it's a valid concern that I didn't think of. Personally, I prefer the convenience of continuing where I left off with as little friction as possible, so I don't even lock the session when the screensaver kicks in. But I never take my laptop outside, and the threat of malware is considerably lower under Linux. If that wasn't true, I would probably also want to err on the side of caution. Choosing a specific key (I have a very conveniently positioned X86WakeUp physical button) or combination for waking up and getting to login prompt seems like a good idea in that case.