We went on vacation recently and I fed my 12 mth old dd on the plane, I never used a blanket over her head as she would have thought I was trying to play Peek-A-Boo and it was too hot on the plane. I do always make sure I wear something easy to feed in and something that can cover up quite well. No one said anything (and it's a good thing for them otherwise they would have gotten an earful!). I think forcing someone to use a blanket is in the same catagory as telling someone to bf in the bathroom, I would like to see an adult eat their lunch with a blanket over their head to see how comfortable and easy it would be!
I like the new symbol as well. I always wondered why the feeding symbol in public bfing rooms (malls, etc) showed a bottle when a bottle can be given anywhere.