The Internet has made it possible to see more of this, because Islamic radicals have found the Internet a cheap way to reach supporters who can either provide cash, or volunteers for terrorist activities. While more young Moslem men use the Internet to view porn than to seek out terrorist web sites, there are enough terrorism enthusiasts out there to keep the terrorism sites jumping. But these sites (which can be found via a Google search for jihad and al Qaeda) make it clear how dark the dark side it. While many of the sites are in Arabic, they contain lots of illustrations that make it very clear what these people are all about.
Hitler, Stalin, Mao, Tojo and Pol Pot didnt kill over a hundred million people all by themselves. They plenty of willing helpers. Many of those willing helpers are still around, and have no regrets. The Internet has made it easier to recruit an army of cold blooded butchers, but it has also make it possible for anyone to stare right into the face of evil.
We tend to forget that the classic evil empires of World War II Germany and Japan, and Stalins Soviet Union, were propped up by the enthusiastic support of millions of people. The same thing is happening with al Qaeda and Islamic terrorism. A truly horrendous evil has seized the imaginations of millions of Moslems. They willingly and energetically support the use of murder and terror against the infidel (non-Moslem.) This is a very ugly story, with a lot of very ugly details, and thats probably why it doesnt get covered much. Moslems in general, and Arabs in particular, have developed an imaginary "war on Islam," and many are eagerly supporting those who would "fight back" via terrorism and mass murder.
Fighting this mass hysteria in favor of death and hatred is difficult. The Arab media, like media everywhere, find that hysteria sells. Moslem governments, most of them dictatorships of one sort or another, find this hatred of "Infidels" means less time spent on hating local tyrants. In the West, it is considered somewhat unsavory to wage war via media manipulation. So counter-terrorists trying to deal with the messages of hatred have to fight a two front war to accomplish anything. The United States is doing this, although you don't hear much about. American media don't like to touch this kind of story, as it is a little too close to home. But the U.S. government is out there trying to deliver the message that peace and democracy is a better deal than hatred and terrorism. It's a hard sell.