The notion of culture is used here to indicate a universal social phenomenon, not the specific organized forms like film or theatre. In this sense we see that culture is an indispensable element of all human groupings. To the outside of this grouping it appears as a lack of function or explanation and is unique to them. In this way it makes up the identity of the grouping and draws the border to other groupings (that it's members might otherwise belong to).
From the perspective of a grouping member taking part in a culture - like in an event, a behaviour or a way of talking - is a way of expressing he feels himself belonging to that grouping.
So culture is a very important element of human existence but one that can not be organized from the outside of each grouping. In other words, any 'global network' activity can only connect between the existing communities - the ones in the real world, not in cyberspace.