Also same with street side functions, processions and religious events.
Everybody feels they have freedom to steal. No wonder corruption is so difficult to eliminate in this country.
Frontline magazine did a study which showed that a huge amount of power theft was occuring at industrial consumers. http://www.flonnet.com/fl1906/19060950.htm (it's a little dry in the typical Frontline style. I hope you will read it).
Also, you didn't mention businesses in places in Chandni Chowk, Lajpat Nagar etc? Given the other "cost-cutting"^Wtax-evading measures they take, I would feel very confident in assuming that they don't pay for most of their energy use.
For one there are several different types of corruption, I usually treat them as small c corruption and Big C "Corruption".
A break down for Small C corruption for Bangalore between June July can be got here - from ipaidabribe:
http://www.facebook.com/photo.php?fbid=413057582064179&s...
(for some reason their site doesn't have the photo, so had to dig up their Facebook page)
Then there is large 'Corruption', the purvey of our politicians which has to be treated differently. Thats what we need the Lokpal bill for.
The new changes to service tax though, will slowly close many of the loop holes though.