Bixler

I tend to say "nay" because I'm always very careful with my electronics – three years in and nary a scratch on either screen. Curious to hear others' experiences though.

My current 3DS hasn't had any screen protector. No visible scratch.

I generally say "yes," because judging from the condition of the used systems I've seen, most people seem to excrete a combination of coarse sand and oily grease through their fingers.