Nearly all DHT implementations vulnerable to 'merge' bug.
As DHT implementations proliferate and harmonise, the prospect of multiple widely-deployed applications using the same or compatiable DHT implementations is increasingly becoming a reality. There are a large and increasing number of DHT libraries out there, such as Entangled , and FreePastry, being used by an increasing number of applications.
However, most of these implementations are vulnerable to a simple but subtle bug: They have no way of distinguishing one DHT network from another. Although each application's DHT network or networks start off separate, if, by chance or deliberate action a node from a different but compatiable DHT is introduced, the 'self healing' property of DHTs will ensure that, sooner or later, the two networks become merged into a single DHT.
This is not a problem for single-purpose DHT implementations such as those used by BitTorrent or Overnet, since they generally establish a single DHT with all compatiable clients participating in any case. Nor is this a problem for networks designed with heterogenous applications in mind, such as CSpace. However, this still leaves a number of DHT libraries that don't fall into either of these categories.
Last night, having finally found my Cybook again, I downloaded Cory Doctorow's latest novel, Little Brother. Like all his other works, it's available for free download under a creative commons license, and like all his other books, it's excellent.
Unlike his other books, Little Brother is scary. Not scary in a "something's creeping up behind you" sort of way, but scary in a "completely plausible, yet utterly terrifying" way. The book is set in the (very) near future, and is focused around some of the most surveiled people in society - no, not prison inmates, high-school children. Imagine George Orwell's 1984, only a lot more immediate. Though disturbing enough to begin with, describing as it does worrying yet (alas) completely plausible intrusions in the name of 'security', everything takes a turn for the worse when a terrorist attack sends security paranoia into overdrive.