The Bernie Sanders campaign kicked off its massive volunteer program this weekend by holding nearly 5,000 house parties across the country and unveiling a new organizing app that gives campaign supporters a way to share political information on friends, family, and neighbors.

Sanders’s strategy to emerge from the crowded primary field revolves around energizing and empowering his army of supporters, and giving them easy-to-use tools in the hopes of expanding the electoral map in both the primary and general elections. More than 60,000 people attended the events, which took place in every state and more than 30 countries outside the U.S., according to the campaign.

Sanders, along with campaign manager Faiz Shakir and campaign co-chair Nina Turner, addressed supporters through a pre-recorded broadcast that was streamed at the parties. “So let’s do it, let’s run a historic grassroots campaign,” Sanders told supporters. “And when we do that, the 1 percent can spend all of the money that they want. We’re gonna beat them.”

The campaign’s new organizing tool, called BERN, helps volunteers track potential supporters and voters, allowing them to log the name and background of anyone they talk to, from friends and family members to a stranger on the street. The app will also help volunteers know how to participate in the Democratic primary or caucus in their state and register voters.

On friend-to-friend mode, supporters are asked to add the name, city, and state of everyone they know, information that is then matched to their voter record. The app also asks about the person’s level of support, union membership, and other candidates they might vote for.

Some critics have called the app invasive, arguing that the database of personal information could open non-supporters up to harassment. Though much of the information the app requests is publicly available, critics say that having the data neatly compiled — while not giving people a way to opt out of it — presents safety concerns.

The skepticism appears rooted in (hostility to Sanders and) a basic lack of familiarity with how campaigns work. Voter rolls are public, and the Democratic Party has long been aggregating additional information about voters to aid with fundraising and turnout operations, data that all major campaigns have access to. The difference is that the Sanders app democratizes the process with the goal of expanding the electorate, while the party operations are aimed at identifying existing supporters so they can be motivated to vote. The party data is generally available to campaign volunteers, but because Sanders lowers the bar to volunteering, more people will now have access to the data. The goal, though, is to get more people to vote for Sanders, not to attack Sanders opponents.

To that end, they’ll be relying heavily on supporters.“We don’t think, in the national office, that we have all of the answers,” Sanders said. “Trust me, we don’t. Every person out there knows your own community better than we do. Can you put on a concert, can you have a potluck event? Whatever it may be, bring people together. Develop a sense of community, reach out to people who might feel uncomfortable about being involved in politics.”

Sanders has a list of 1.1 million people who’ve pledged to volunteer so far, meaning roughly 6 percent showed up to a house party over the weekend. Sanders told them that the goal is to have volunteers engaging on social media in addition to the “old-fashioned stuff,” like knocking on doors and handing out literature. Unlike the typical political campaign, where volunteers work under the supervision of paid campaign staff, Sanders volunteers will be given the tools to help grow the movement at an exponential scale, free of the restraints of traditional top-down campaigns.

“And remember,” Sanders said. “It’s not Bernie! It’s us! Don’t forget that: Us! Us! Us!”

Sanders supporters, with and without previous organizing experience, gathered this weekend in libraries, living rooms, restaurants, and classrooms. They wore Bernie shirts, made Bernie signs, Bernie cookies, and Bernie cakes. Some groups even received a surprise phone call from the candidate himself.

In Oakland, Bay Area Muslims for Bernie held its party at a local Palestinian street food restaurant. A group of around 25 people, which included supporters from Egypt, Iran, Morocco, Yemen, Afghanistan, and around the United States, joined the organizing kickoff. “We even had refugees attend who cannot vote but still wanted to support and promote Bernie’s message,” Reyhaneh Rajabzadeh told The Intercept in a message.