From tweets to twitpics to YouTube videos, amateur, user-generated content has become a staple raw material for many professional news organizations. With NBC News’ acquisition of Stringwire, however,  the evolution of user-generated news is embarking on a new phase.

The brainchild of Phil Groman (NBC describes the deal as an “acquihire”), who developed the technology while at NYU, Stringwire scours Twitter to identify users who identify themselves as on the scene of a breaking news event and then sends them a live link. When clicked, the link automatically launches the Stringwire web app, which pulls live video being shot by the Twitter user back into NBC News’ control room, where it can be previewed and put directly on the air.

“You could get 30 people all feeding video, holding up their smartphones, and then we could look at that,” NBC News chief digital officer Vivan Schiller told the New York Times. “We’ll be able to publish and broadcast some of them.”

And with that, witnesses whom news organizations have heretofore treated as sources will be transformed into NBC journalists, albeit (presumably) uncompensated ones. That may seem like mere semantics, but traditionally news organizations have very different sorts of relationships with the journalists that work for them and the sources those journalists rely on — different legally, professionally, ethically and editorially.

Social media platforms and tools are transforming the practice of journalism, and for the most part that’s been a good thing. And as my colleague Stowe Boyd pointed out earlier, NBC News deserves credit for thinking like a software company in seeing the potential of Stringwire. Let’s just hope it has put as much thought into navigating the increasingly fluid and still largely uncharted roles of newsmaker, news consumer, reporter and publisher.