they are pure evil,
seriously though, some kids laugh all the way watching them, while other get very scared...
i was at a friend house once, and clowns came on tv, his little girl like 3 years old started screaming and crying and came running to me, i left her up in my lap, telling its ok sweety, but man i could feel the little poor kid heart beating like crazy, there is no doubt in my mind that she was seriously terrified right out...
i personaly never liked them or thought they are funny...