Heidegger's project is a 'questioning concerning technology' rather than a brief against technology. It is a questioning that aims to disclose a mode of being within which live as embodied indwelling beings.
We are in the world of technological being. This 'in the world' suggests that the user is enframed by this mode of being: thus if you want to drive a car you must conform to its requirements in order to use the tool , the roads, traffic lights, traffic codes etc. -- and not the other way around. If you surf the Internet, then you must do so within the limits of the Internet including your particular provider/browser you happen to be using. We are ourselves transformed into the instruments of our own technologies, information and otherwise.
Technology enframes a mode of being. Consider Australia's iconic Snowy Mountains Hydro-electricity Scheme of the 1940s. This is one of the wonders of industrial capitalism in Australia--it signifies what modernity was all about. At one level, the Snowy Scheme is but a series of dams to turn the waters westward across the plains to Adelaide. To achieve a drought proofing the scope of the Snowy and Murray Rivers are altered, their flow dammed into the requisite domain and so contrrolled by a series of locks for irrigation. A mode of life has developed based on irrigated agriculture and cities dependent on the river. We live this mode of life but do not question its technological being.
This turning a river into a machine for power and agriculture forces a questioning; a challenging of the hydro-electric plant reveals the river in terms of an elimination of its organic history or its contours of floodplains, wetlands and biodiversity in favour of the river as a resource for hydroelectric power and agriculture. So what Heidegger is doing is reflecting on the difference between modern technology (Snowy Scheme) and premodern technology (the windmill) and to argue that this difference reflects the essence of technology.
What is this technological mode of being for us in Australia? It signifies a calculative rationality, a mechanization of nature, cities as machines, an efficient industrial enterprise, the transformation of the family farm into modern agribusiness of cotton, rice grapes and piggeries---what Heidegger calls the mechanized food industry.