Don't drop 2 handed items out of your backpack with only 1 free hand.

[Daisybell]

I think it poses the biggest issues for characters who have one arm. If you lose an arm and you instinctively reach for your taser, you drop it and you can't pick it back up again, and then some little staffie comes and steals your taser. I think a nice little message like "You can't hold that with one hand!" message would work nicely.