While the person that softlinked double negative below is technically correct, I'd like to defend hojotoho’s definition of the term as wholly appropriate to the context of usage that he gives.
Yes, under everyday organic usage, one would strip of the “dis-“ prefix to revert the word to its antonymical and original meaning – “mediate.” However, the term disintermediation has a very specific meaning within the ecommerce world. Specifically, it’s used to describe the use of information technology and advanced logistics to collapse supply and distribution channels. Eliminating the consulantspeak, it’s using the web to get rid of the middleman as in, “How are our prices so low? We eliminate the middleman and pass the savings along to you!” In traditional mass market commodity economics, the intermediator takes care of the mess of aggregating goods and services from many manufacturers and providers, providing a single point of reference to the end user. Since this is market economics, this distributor tacks on a margin to cover his costs and make a profit, the margin in theory regulated by competition.
To use hojotoho’s example, Napster disintermediated the record labels by eliminating the need for physical storage media to distribute music. Thus, the producers of music, musicians, were able to send their product directly to the consumer/end-user, the listener. Upside, exploitative record labels threatened with extinction. Downside, no real way to monitize this distribution back to the musician, unless you figure on all recorded music as advertising and promotion for live performance. Sucks if you’re a studio/lab music type.
All of which brings me back to my original point – the record label executives and lawyers claim to be defending the moneymaking power of musicians by defending the distribution channel (cd sales- moving plastic) from disintermediation by intellectual property piracy. Thus, standing opposed to disintermediation they are rightfully referred to as antidisintermediationists. Calling them “mediationists” would fail to carry the semantic overtone of their reactionary, some would say retrograde or even counterrevolutionary, stance.