Serious question actually.
What's the real world use-case for this? How is security handled? If my browser was able to talk directly to my Riak cluster, all my data would be open?
http://blog.mozilla.com/data/2010/05/18/riak-and-cassandra-a...
In it they discuss security issues addressing riak, cassandra, and hbase.
One poster mentioned the http interface, but also there are hooks within webmachine that would allow for some authentication as well - mentioned in the article.
Riak doesn't have authentication or authorization built-in. It is on their radar. We have a light-weight backend for that stuff which doesn't know about most of our data. It obviously has to know about users, but other than that it just serves and stores JSON.