How to Implement Digital Community Currencies with Ethereum?

Oh, you mean we could create some nodes restricted in a certain ip range for running my own blockchain, so that the node outside the ip range cannot verify the transaction.

But the problem of digital community currency is that we should prevent token from transferring to the address which is outside the local region. I think in your case, people could still transfer token to the address outside the region, and the transaction is verified by the node in the specific ip range.