Age limit for small kids entering cinema???

Hai.... No offense please... I was just thinking would i be inconsiderate for couples with small children whom wish to watch movies in the cinema & had to bring along their small kids??? But then again, are they being fair to others whom lined up to buy ticket, paid for it & came to cinema mainly for the purpose of enjoying the movie without any hiccup together with boombastic sound system which could never be replaced to the kind of sound system which they have at home??? Some of these kids whom followed their parents or family to cinema are soo small; toddlers & also babies... I was thinking "come on, u got to be kidding me?" when i first saw these kids were among those who came for movies.. They could hardly understand themselves; what more to enjoy the movie... So please... Please... Please... Let us be more reasonable & considerate to each other, ok? The loud sound & bright light from the screen in the dark would have been bad enough for small kids... Let us play win win situation here, small kids would not get hurt & those who came to enjoy movie managed to get what they wish for.... Peace....