Bandwidth hogs cannot exist on a per gig data model. They pay per gig, they get their gigs. ISPs make their money per gig. No hogging, just good ol' commerce.
The question of 'hogs' is only appropriate in an uncapped environment. Here its the ISP's responsibility to manage the network so that 'bandwidth hogs' do not affect other users.
Acceptable usage may classify them as as 'hogs', but a management strategy should be all that is needed. Our average users are doing 50 gig/month on a R300 package. They're not 'hogs'. They're just starved of access to data and poor after paying for all those gigs. Some chilli guys have done 200 Gigs in 10 days. They're still not 'hogs' because they're making use of the network. On top of that most are self-managing and are making sure that they don't undermine the operation of the network as a whole.
The user that purposely and maliciously tries to avoid the ISP's management at the detriment to other users on the network may be classified as a 'hog'. Even here, the ISP has to manage the network so that this doesn't happen.
Strategies of pulling desired content closer and providing faster access to alleviate bottlenecks is probably the best strategy.
Even 'hogs' will get tired of buying more and more storage at some point.
An overall policy of network management, user management and content management makes the 'hogs' urban legends.