...why would I ever do that? You leave something worth several thousand dollars anywhere in public you're risking losing it. What are we even debating here?

You might have seen some laptops have screens that fold down, I know MacBooks do. This "clam shell" effect protects the keyboard, trackpad, and even the screen from bumps and jostles. Many laptops when so closed can even fit in a backpack.

So a little trick I figured out is to close my laptop lid and then slide it into a pocket of my backpack. I can then carry it with me when I get up and move around.

So then I can take it with me to eat lunch or an extended toilet break. Maybe some day all laptops will have that feature.