Nothing irritates me more than people who put their seat back on short haul flights.
It's rude and inconsiderate.
I can understand it on longer flights i.e. over night, but for sub 6-hour flights (especially in Economy) no one should subject anyone else to the claustrophobia of a leanback.
I wouldn't do it to anyone else – and I don't want it done to me or the people I'm with.
Thankfully I'm not alone in my complaint – the clever people at http://www.kneedefender.com/ have created a tool to ensure the rude twat in front of you is prevented from encroaching on the limited space you have.
If you can't afford one, the other alternative is to point the airjet above your head at the person who has leaned back. It won't take long for them to move out of the cold air.
I think the airlines should remove the ability to leanback on short-haul, economy seats. If you want to leanback upgrade to business or better where the leg space means you aren't affecting the person behind you.