Err... so which part of "closed source" is the GPL software?
The GPL allows you to use someone else's code with the proviso that you license your code under the GPL as well. Don't like those terms? Don't use GPL'd code.
The IP market is not a free market, you can't really sell IP addresses like that. Instead what would happen is that HP would either have to become an ISP (or spin off an ISP division) or release the block(s) back to ARIN. ARIN would then assign them according to their existing policies. Further more, new blocks cost a yearly upkeep fee whereas if you were grandfathered in (like HP was) then there is no fee.
Because of this there isn't really any incentive at all (except perhaps some very very small PR) for returning blocks, and that's not even thinking about the costs associated with moving to a new IP range or the abject stupidity of NAT.
Ebook piracy shows no such thing. What is shows is that when your trying to sell something in a market where the cost to copy is nil, then your business model is broken. Artificial scarcity on the internet is simply impossible and at best all you can hope for is to get people to pay for convenience.
Obviously writers can't make money through concerts or t-shirts; but there will always be a market for those of us of enjoy real, physical books. There is also a market for public speakers, many of whom are writers. Does this mean that all writers will be able to make a living? No. However it's neither reasonable nor feasible to allow everyone to make a living doing what they enjoy.
If all else fails, immortality can always be assured by spectacular error. -- John Kenneth Galbraith