Three years after the Occupy Wall Street movement began, an unlikely conflict has emerged over one of the cause’s most precious tools: a Twitter account.

During the primacy of the Occupy movement in New York, people across the country followed @OccupyWallStNYC and other social media accounts to track the latest developments, from encampments to conflicts. Now one group of activists is accusing a former comrade of taking unilateral control of the shared account and locking out the organizers he had once collaborated with.

According to a lawsuit, which was filed on Wednesday in State Supreme Court in Manhattan, the Twitter account was created in summer 2011 by Adbusters, the Canadian magazine that first called for an occupation of Wall Street. The resulting protests began on Sept. 17, 2011.

Adbusters turned the account over to Marisa Holmes, the lawsuit said, a filmmaker and activist who had helped to moderate Occupy meetings in August 2011 in Tompkins Square Park. Ms. Holmes, in turn, gave others access to the account, which now has 177,000 followers.