Are industry giants danger to startups?

Yet another episode of start-up crushing story got unveiled to me , regarding the flight search launch by Google. Is innovation getting a cornered glimpse? Yet there is no way that people can be stopped from giving flight to their ideas. But when giants like Google try to expand their presence over a lot of areas, will it cost much to start-ups. Does any startup founder-to-be just modify his ideas because of this? Does this move from a giant company a threat to freedom of innovation? Well, this sounds crazy.. Do you join a giant company to be part of their ideas or do you create one out of your ideas, yet still wait to be crushed by the giant? I am not pessimistic here though !