Media transport a message from a sender to a recipient. Media do not change the message transmitted. Media do, however, invite certain message types more than others. Thus, certain media are more AppropriateMedia for certain types of content.
Traditionally, broadcasts are prepared beforehand and then sent out to the listeners. If the host feels like it, a small number listeners can be invited to phone in and give some feedback, or an even smaller number of guests can be invited into the studio. This invites content edited by a few, and questions discussed by experts. Archiving happens on a very small scale via tapes. Distribution is limited by the power of the station, but basically unhindered. Radio and TV can be controlled by legislating the use of spectrum. In a crisis, TV and Radio can be used to distribute messages even when movement on the streets is impossible. Radio and TV reach illiterate people. This is why Radio and TV stations are the centre of political attention during a crisis.
Newspaper articles are also prepared beforehand and then sent out to the readers. Feedback is even more limited than for Radio and Television; all you can do is send in letters to the editor, which may or may not be printed. Censorship is much easier in printed media. The distribution of large numbers of prints requires a well developed infrastructure. This is easy to control, thus controlling printed media is easier than controlling pirate radio or TV stations. Printed media only reach readers -- literate people. This makes it harder to reach the masses.
The web requires even more infrastructure than newspapers -- it requires cables, modems, and computers. When the physical layer exists, however, the content layer is more or less independent of it. This is why people can connect to the net without having to ask all the other nodes -- they only need one node to attach to in order to be connected. The internet is only easy to control at physical bottlenecks. This is why control over the net starts at Internet Service Providers (ISP). Every person connected to the Internet needs an ISP. When all the ISPs are connected to a national or regional backbone, and only the backbone is connected to the rest of the net, then it can also be used to control content on the net. The Internet is mostly a textual medium; it only reaches literate people. This makes it hard to reach the masses. The infrastructure is expensive, which makes it even harder. On the other hand, on the Internet, distance is practically not important. Once you are on the net, you are on the same net as the rest of the planet. Usually, information on the web is stored on web servers. In order to spread a message, you need a web hosting service provider which maintains a web server for you. Information flows usually in one direction only. Authors upload to their web site, from where it is distributed. If at all, feedback is usually sent via mail.
A wiki is a website on the WWW where readers usually are given more power. They are allowed to edit the pages. From then on, it is is possible (should the person paying for the web hosting allow it) to share information between all readers. This still reaches only literate people connected to the web, but now everybody can contribute just as easily, without further knowhow being required. Short of direct face-to-face meetings, this is one of the few ways where every reader can truly be an author at the same time.
This is why we feel that wikis offer an unprecedent amount participation, as long as web hosting is not controlled.
I believe feedback to newspapers is much easier than television. No newspaper would sell without community interest. Letters to the editor, classifieds, personals, advertisements, obituaries, city sections, and bulletin boards are all examples of where community members have a hand in what gets printed. For local community papers, even articles are written by community members. Television stations on the other hand control their airwaves 100%. It's relegated to gimmicks where viewers can impact programming, such as CHUM's Speaker's Corner or the minimal email read back at the end of news broadcasts. In fact, it is so bad, that at least in the United States and Canada, the private broadcasters and distributors are forced (by law) to pay for a separate public access television station, not to mention in Canada the national Canadian Broadcasting Corporation.
I also don't think that controlling newspapers is easier than television stations. In Canada, there are fewer television stations owned by even fewer conglomerates, whereas there are many many newspapers owned by a wide assortment of interests, right down to the local neighbourhood community newsletter and the heavily competing alt.culture broadsheets. Creating newspapers is an unregulated affair in Canada, whereas creating television stations requires a broadcast license. Because the government regulates television stations, the government has been able to control what these television stations broadcast, even so much so that during a license review, television stations may be very cautious about what they say. I believe this system is replicated to some degree in almost every modern country.
Recently, CanWest? Global bought hundreds of newspapers from Hollinger. Concerns (legitimate) have been raised that the newspapers will now have to watch what they say so that the television license process doesn't get adversely affected. But note how it is the television process that introduces censorship, not the newspapers. -- SunirShah