I'm sure there is a reason you need to have your seat in the upright position for takeoff and landing, I'm guessing it's safety, so why can't people place their seat in the upright position?
It hasn't happened recently, but it has happened more then once - people reclining their seats for takeoff. This really annoys me, not so much because it gives me less space- I'm small and fit ok in the seat, even with a seat reclined. But, I can't imagine bashing my head into the seat in front of me during a failed takeoff would feel very good.
Yet, on at least 2 flights I have had this happen, and while I do travel more then the average person, I don't travel THAT much. The first time was on a Virgin Atlatic flight, and the seat back was mostly plastic, I think it would have hurt if I hit it with my head. A flight attendant did not notice this and so it was not corrected. Then it happened again last year. The flight attendant did tell the person to put their seat in the upright position, they pretended and then didn't do it.
In both cases I really should have said something to the person, but I was a wimp and I didn't. I figured they would learn their lesson better if I sued them for my injuries. Yes, I did actually think that in my head. Going ahead I will say something - why should I risk bashing my head for someone elses comfort?
Sorry for the rant, but I had to get it off my chest.