A source close to Vice Media confirmed on Friday that writers working for the company have voted to join a union. The move makes the New York-based alternative media outlet the latest to join a growing group of new-media entities whose editorial operations are now unionized. Like their predecessors in that group — including Gawker Media and Salon — Vice employees have chosen to join the Writers Guild of America, the same union that represents Hollywood screenwriters.

In addition to the source I spoke with, who confirmed a report in the Wall Street Journal, a writer who attended a meeting of the Writers Guild where the vote was tabulated — freelance writer David Hill — posted a comment on Twitter about the successful union drive. Several other Twitter users, including the National Writers Union, also confirmed a successful vote.

Upstart media outlets like Gawker and Vice were once the lawless cowboys of the new-media frontier, breaking all the rules and somehow getting away with it — but now they are being reined in somewhat by their own writers, many of whom are looking for the kind of stable environment and pay scale associated with more traditional media outlets.

Gawker’s writing staff voted to unionize in June, after a typically public free-for-all debate that spilled over onto the site’s Kinja blogging platform. In Gawker’s case, the union drive was just one subplot in what seemed to be an ongoing drama involving founder Nick Denton and his goals for the site. Not long after the drive, several senior writers and editors left the company following the publication (and later removal) of an contentious story involving a married media executive and a gay stripper.

Salon followed Gawker into the Writers Guild shortly after Denton’s staff voted, and then Guardian U.S. writers voted to join the Newspaper Guild just last week. Vice Media, which has about 700 employees, is by far the largest digital-media entity to have a union.

Salon has been around since the mid-1990s, but Gawker and Vice are somewhat newer to the digital media game (although Vice has technically been around since the 1990s, when it was a printed magazine about music and alternative culture based in Montreal). Both have been going through a process of growing up to some extent: Gawker’s Denton has renounced some of his company’s earlier principles and said he is trying to become nicer, and Vice has raised so much money from existing media entities that it is now valued at more than $2.5 billion.

Some of the writing staff at these outlets clearly feel that if their employers are growing up and becoming legitimate businesses, they would like some of the protections and security that come with traditional media jobs — although executives for both say their pay and benefits are competitive. Whether bowing to union demands makes Gawker and Vice less flexible in the future or simply less stingy remains to be seen.

In a statement released after the union vote, Vice founder Shane Smith said:

“I’m so proud of all my perfect diamonds here at VICE. Every single day your ideas and work continue to blow me away. I am proud to support all of you – and as an old grey-haired man all I want is for my beautiful VICE family to be happy – those writers who voted to unionize and those who did not. I love you all, and together we will conquer the world.”