Do you take you laptop to your local coffee shop? Are you tired of Nosy McSlacker reading over your shoulder? Or on the plane next to Halitosis Mouthbreather? You should knit a Laptop Compubody Sock.* Sure you'll look ridiculous but your words are like your children and should be protected from lurkers.
Bonus: If you're a man, you could leave an opening toward the front area and no one has to know what your hands are doing. Just be sure to pull your face out in time (or not, your choice).
*Thanks to SuperforestNYC for the link. Also, I kind of want to make one just for kicks.