I've been watching this one evolve recently, and have to agree with those who suffer at the hands of those 'asserting their right to recline'. 121decimal5 has my genuine symapthy and support.
The CAA in conjunction with some eurocrats is at present re-evaluating the minimum seat pitch/width requirements, in light of the fact that people on average are much taller than they were when said limits were introduced. The re-evaluation, I undertand, is looking only from a safety perspective, and not from a comfort viewpoint.
However, there is a very real health threat that is well established medically, that being the risk of deep vein thrombosis. This can develop (and has) when passengers sit with legs pinned stationary for many hours in economy. This is medical fact. The result may be that you feel unwell after 12-24 hours, and can die (blood clots move to lungs etc.. It does not happen often, but I do think this needs considered by CAA et.al.
The Airlines know that passengers despise the lack of room in economy, but where they must compete on price, and their is no regulatory limit (current CAA pitch minimum is 26" I think) then leg room is a casualty.
Their is light on the horizon, at present American Airlines are reversing the trend and changing their aircraft so that coach class (economy) has more legroom. I dont know of any others, but lets keep hoping that someone else will see the light.
If you knowingly recline your seat to someone elses discomfort then you should be asked to leave (at 34,000 feet)!