The chief executive of Reddit has apologized to its community of users for actions that led to an embarrassing revolt which took down some of the social bookmarking site's largest communities, particularly video gaming forums that drive a good deal of the site's traffic.

"We screwed up," Ellen Pao said today. "Not just on July 2 but also over the past several years."

Pao apologized for poor communication with and broken promises to the largely volunteer force of moderators, creating a ferment where Reddit management appeared high-handed and indifferent to the users who create the vast majority of content that make the site so valuable. Indeed, a petition demanding Pao's ouster had gathered 16,000 signatures as of Friday, but already had 10,000 endorsements three weeks before.

On Thursday, a moderator for Reddit's IAmA forum — where persons in the news up to and including the U.S. president have held town-hall style virtual meetings — was summarily dismissed. In response, the moderators of IAmA and other large subreddit forums took them private, effectively closing them off to the public.

Pao today said Reddit "acknowledge[d] this long history of mistakes," and promised reforms to help moderators do their work and better communication between administration and volunteers.

"I know these are just words, and it may be hard for you to believe us. I don't have all the answers, and it will take time for us to deliver concrete results," Pao wrote. "I mean it when I say we screwed up, and we want to have a meaningful ongoing discussion. I know we've drifted out of touch with the community as we've grown and added more people, and we want to connect more."

On Friday Pao also acknowledged that years of promises to support moderators had gone unfulfilled. Pao offered no explanation for why the IAmA coordinator, Victoria Taylor, was dismissed. Moderators who relied on her to help run the popular Q&A sessions were furious at the blindside change.

Reddit, owned by Condé Nast Publications since 2006, is the No. 33-ranked website globally according to Alexa.com, and No. 10 in the United States, from which it draws more than half of its readership.