Shares in data centre operator NEXTDC fell 42 per cent in a single day after the company revealed that delays in getting power to a proposed expansion of its massive complex in inner-west Melbourne meant its future earnings would be cut by a third.

A neighbourhood dispute and an act of civil disobedience, residents parking their cars in the street to deny trucks access, had stopped the march of industrial-scale power poles that would provide the juice for the next stage of the data centre.