Isn't this just a resource which assists counterfeiters?
Without this list - counterfeiters would need to re-use addresses from a small pool in order for their coins to pass the basic 'public-address shows value in blockchain' test.
What is the motivation for publicly releasing this list? Are you likely to do this in future? (I'm hoping not)
Even if you have no intention of maintaining any sort of dupe-public-key tracking/reporting app - someone else might want to, and having a list of *all* released coins might reduce the usefulness of that. Being able to verify a key by search once you know it is fine - but I don't think they should be listable.
The list is so people can match the 8-character substrings to the full bitcoin address. It is also incomplete, I have plenty of addresses NOT on the list.
The list would be pretty easy for someone else to come up with from the block chain. The loading coins transactions are quite characteristic and would be easy to search for or spot - they don't look like typical transactions - they're made with the rarely used "sendmany" RPC call and already stand out for that reason alone. It is no different with BitBills. It is fairly easy to find the addresses of other Bitbills. Here is a transaction that loads 90+ BitBills. http://blockexplorer.com/tx/661c4f738aab05dc57030814dec5b581793967c5a21b845c4ed9ef3dbf3030a3 , if I were more nimble at mass-searching the block chain with a script, I wouldn't be surprised if I could come up with a nearly accurate list of all circulating BitBills. Here's another,
http://blockexplorer.com/tx/c262797f2d7c790db63a4e5ce4b4bb2a511de2c0e1516dd6d7b6b6f0c749f5eaWhile the concerns are valid from an information-theoretical perspective, I am really not concerned about counterfeiting in a practical sense. For one, Casascius bitcoins are never going to get to the point of ubiquity because I already know that I am only going to have the time and patience to produce so many, and by then, I expect someone else will have outdone me both in quality and price. And who's going to pass them, and how? It's a limited audience, a small community. USD counterfeiting is commonplace yet the odds of me selling something on Craigslist and being offered counterfeit USD as payment, even in a large city or community, is very low... the odds of getting fake Casascius physical bitcoins has got to be an order of magnitude lower.
If the most I plan to create is a few hundred or a few thousand, that's just not worthwhile for a counterfeiter to even bother. By making them, I really just want to tell the world that this is possible, that bitcoins don't have to be purely digital, and that they should copy me. Here you have me in the rare position of begging for competition, sort of the same odd way I promoted mining months ago when common sense would say that I should help keep the difficulty as low as possible.