Do you know, What is CIS (Central Internet Servers) ?

By 1998, a new form of the darknet began to emerge from technological advances in several areas. The internet had become mainstream, and as such its protocols and infrastructure could now be relied upon by anyone seeking to connect users with a centralized service or with each other. The continuing fall in the price of storage together with advances in compression technology had also crossed the threshold at which storing large numbers of audio files was no longer an obstacle to mainstream users. Additionally, the power of computers had crossed the point at which they could be used as rendering devices for multimedia content. Finally, “CD ripping” became a trivial method for content injection.

The first embodiments of this new darknet were central internet servers with large collections of MP3 audio files. A fundamental change that came with these servers was the use of a new distribution network: The internet displaced the sneaker net – at least for audio content. This solved several problems of the old darknet. First, latency was reduced drastically.

Secondly, and more importantly, discovery of objects became much easier because of simple and powerful search mechanisms – most importantly the general-purpose world-wide-web search engine. The local view of the small world was replaced by a global view of the entire collection accessible by all users. The main characteristic of this form of the darknet was centralized storage and search – a simple architecture that mirrored mainstream internet servers.

Centralized or quasi-centralized distribution and service networks make sense for legal online commerce. Bandwidth and infrastructure costs tend to be low, and having customers visit a commerce site means the merchant can display adverts, collect profiles, and bill efficiently. Additionally, management, auditing, and accountability are much easier in a centralized model.
However, centralized schemes work poorly for illegal object distribution because large, central servers are large single points of failure: If the distributor is breaking the law, it is relatively easy to force him to stop. Early MP3 Web and FTP sites were commonly “hosted” by universities, corporations, and ISPs. Copyright-holders or their representatives sent “cease and desist” letters to these web-site operators and web-owners citing copyright infringement and in a few cases followed up with legal action [15]. The threats of legal action were successful attacks on those centralized networks, and MP3 web and FTP sites disappeared from the mainstream shortly after they appeared.