I think that closed-source cryptocurrency questions should be declared off-topic, because they are usually impossible to answer. Example:
After having launched bootstrap Clearinghouses on all major continents, they are fully reconciling transfers in less than 400 ms with competition and 200 ms without. "Reconciliation" is confirmation?
My country cryptocurrency illegal. No can to try. Please help.
Even if they are answered by their developers, it's not possible for other members of the community to "cross-examine" their answers.
This might prevent questions about cryptocurrencies that later become open source. For example, we had a number of good questions asked about Ripple that were answered by their developers.
We could lessen that by allowing questions about those currencies if their creators plan to make it open-source.
This shouldn't be taken to mean that all software that is closed source is off-topic. For example, a question that asks about how to use blockchain.info's API would still be on-topic.
This question appears to be off-topic because it is about a closed-source cryptocurrency. http://meta.bitcoin.stackexchange.com/questions/629/suggestion-closed-source-cryptocurrencies-should-be-off-topic