MSNBC.com, the online home of NBC News, has acquired newsvine.com, a Seattle-based social media news website. Newsvine describes itself as “a giant collection of news from all over the world, contributed and controlled entirely by users.”

The site does not have editors. Instead, it considers its users to be the editors: adding, voting and commenting on stories, which may come from a variety of established news services, to determine popularity. The “most active” story as of this writing is msnbc.com’s purchase of Newsvine.

Newsvine users create their own profiles, and contribute stories. A user named Marilyn L., who describes herself as an “artist and art director, web standards enthusiast [and] photographer” contributed several stories tonight about the msnbc.com/newsvine.com transaction.

In a press release, msnbc.com said it hopes the combined assets will “deliver tools that offer users a richer news experience and enable advertisers to interact with consumers in new ways.”