Not long ago, the path by which the recent Justice Department scandal traveled from tidbit to tsunami would have been seen as an exotic trip through an unknown land. These days, it’s almost routine. A prominent blogger — Joshua Micah Marshall of Talking Points Memo — posted an item last December about a US attorney who had been fired for mysterious reasons. Marshall asked his readers for help. And in the weeks and months that followed, they responded by sending him similar tales. Marshall and his posse of blogger-reporters kept the story cooking on Talking Points Memo and a companion site, TPM Muckraker. The mainstream media finally noticed that the Bush administration had been playing politics with federal prosecutors. Soon, the Justice Department was in full meltdown mode. And, in late summer, after many months of twisting slowly, slowly in the wind, US Attorney General Alberto Gonzales finally resigned.

That this tale of media ecology now seems unremarkable says much about how rapidly the media have evolved in the Internet age. At a moment when the traditional media are hemorrhaging readers, viewers, and listeners, a new type of media — democratic, decentralized, grassroots, melding elements of journalism with political activism — is thriving. The animating idea behind the most innovative projects is that news is a conversation. No longer should readers, viewers, or listeners be seen as passive recipients of whatever the media feel like feeding them. Now we can talk back — and, more importantly, participate.

It is a remarkably open moment, similar to radio in the early part of the 20th century. As with radio, some corporations — in this case, the telecommunications giants — would like to bring that moment to a close by pricing small players out of existence. The threat is real; if “net neutrality,” the term for the equal access we now enjoy, is lost, we’ll be getting most of our online content from the same media giants that dominate broadcast, cable, and print. For now, though, the open Internet is enabling grassroots media on an unprecedented scale.

Consider this: were it not for YouTube, Virginia voters never would have seen Republican senator George Allen blurt out the vaguely racist word “macaca” at Democratic rival Jim Webb’s dark-skinned, video-camera-wielding aide last fall. Not only would have voters likely re-elected Allen, but today he might well have emerged as a leading candidate for the Republican presidential nomination. Instead, he’s back home in Virginia, wondering how it all went wrong.

Or look at MoveOn.org and Daily Kos, two websites devoted to political organizing from a progressive point of view. Such sites have proved so adept at generating money and excitement that they may well have been indispensable to the Democrats’ taking back both branches of Congress last fall. (Not that such sites can’t sometimes prove to be a mixed blessing — witness how the right mobilized over MoveOn’s recent full-page ad in the New York Times asking whether General David Petraeus might prove to be “General Betray Us.”)

Indeed, Internet-based political activists — the “netroots” — have become such a crucial part of the Democratic and progressive base that Jonathan Chait, whose magazine, the New Republic, is frequently lambasted by these activists for its insufficient ardor on behalf of progressive causes, has called them “the most significant mass movement in U.S. politics since the rise of the Christian right more than two decades ago.” And that’s just the overtly political side of the new media. If anything, the effect on journalism may prove to be even more revolutionary.

Dan Gillmor, who popularized the term “citizen journalist” in his influential 2004 book,  We the Media: Grassroots Journalism by the People, for the People , likes to refer to these newly engaged, interactive news junkies as “the former audience.” Gillmor writes: “Tomorrow’s news reporting and production will be more of a conversation, or a seminar. The lines will blur between producers and consumers, changing the role of both in ways we’re only beginning to grasp now. The communications network itself will be a medium for everyone’s voice, not just the few who can afford to buy multimillion-dollar printing presses, launch satellites, or win the government’s permission to squat on the public’s airwaves.”

What might this conversational, revolutionary news model look like?
• In an attempt to combine the social-networking power of sites like MySpace and Facebook with journalism, a nascent, experimental project called NewsTrust encourages participants to rate news stories, media outlets, and even one other. Unlike the more popular Digg or Reddit, which asks users only if they like or dislike a particular story, NewsTrust users are presented with a wide range of criteria, including thoroughness, fairness, and sourcing. It’s the classic “wisdom of the crowd” notion — the best and most important stories should rise to the top, regardless of whether they appeared in the mainstream media, on an alternative website, or in a blog.