Ruling on eating chicken that was slaughtered by machine
Question

                To slaughter chickens in an abattoir, they put one thousand chickens under one machine and say “bismillah” only once then they slaughter all of them at once. They wash all of them in one big pot without changing the water, thus every time they wash a chicken this makes the whole water unclean. What is the ruling on eating these chickens? If we buy the chicken uncooked so that we wash it does it become halal? And what if it was cooked in restaurants for example, as they do not wash the chickens before cooking them?.
Praise be to Allah.
    There is nothing wrong with slaughtering 
    chicken by means of modern machines, so long as they are sharp and they cut 
    the throat and the oesophagus. If the machine slaughters a number of 
    chickens at once, then it is sufficient for the person who is operating the 
    machine to say Bismillaah just once when he starts operating it, with the 
    intention of slaughtering them, provided that the person who is operating 
    the machine is a Muslim or a kitaabi (one of the people of the Book, i.e., a 
    Jew or a Christian). 

    Fataawa al-Lajnah al-Daa’imah 
    (22/463). 

    With regard to what you say about the method 
    of washing them, if washing them in this way takes away the blood and they 
    come out clean, then they are taahir (pure). But if some traces of blood are 
    left on them, then they must be washed before eating. 

    It should be noted that the blood which is 
    naajis (impure) is that which is poured forth, i.e., that which flows from 
    the chicken when it is slaughtered. As for the blood that remains in the 
    veins after slaughtering and comes out when it is cleaned and cut up, this 
    blood is taahir (pure) and there is nothing wrong with eating it because it 
    is not blood that has been poured forth. 

    Allaah says (interpretation of the 
    meaning): 

    “Say (O Muhammad
    صلى الله عليه وسلم): “I find not in that 
    which has been revealed to me anything forbidden to be eaten by one who 
    wishes to eat it, unless it be Maytah (a dead animal) or blood poured forth 
    (by slaughtering or the like), or the flesh of swine (pork); for that 
    surely, is impure”

    [al-An’aam 6:145]

    And Allaah knows best.