Documents published by a hacker using the name “Guccifer 2.0” are shedding light on ties between tech industry lobbyists and Congress. Guccifer 2.0 claims to have stolen the documents from the Democratic National Committee, which announced last week that it was a victim of a breach.

The documents leaked by Guccifer 2.0 purportedly include opposition research on GOP presidential candidate Donald Trump, Democratic donor lists, memos, and other files. One spreadsheet posted by Guccifer 2.0 includes a list of members and potential recruits for a fundraising group organized by employees at Facebook and other major tech companies.

The organization, called the Jenkins Hill Society, is a group of political donors focused on raising small-dollar donations for female members of Congress. The group’s roster posted by Guccifer 2.0 lists top lobbyists from major tech companies, including Facebook and Apple, as well as political lobbyists and Democratic staffers.

Co-founded in 2014 by Facebook and Boeing employees, JHS is an informal fundraising group that hosts parties widely attended by Congresswomen and lobbyists, according to Politico reports on the events. The founders, Joy McGlaun and Catlin O’Neill, created the organization in collaboration with the Democratic Congressional Campaign Committee, according to a Facebook page for the group. (McGlaun and O’Neill did not respond to requests for comment.) O’Neill, a former chief of staff for House Minority Leader Nancy Pelosi, now works as a lobbyist at Facebook. McGlaun directs public policy efforts at Boeing.

The JHS roster posted by Guccifer 2.0 seems to have been compiled in late 2014 or early 2015, based on file metadata and the job titles listed in the document — several JHS members now hold new jobs. It’s unclear why the DNC — and therefore the hacker — had access to a list of members belonging to an informal fundraising group focused on small dollar donations. The DNC did not return a request for comment about the document.

DNC leaders suggested that Russian operatives were behind the breach of their networks, and claimed that no sensitive donor information was compromised. So far, Guccifer 2.0’s posts seem to confirm that claim — although the documents contain the phone numbers and email addresses of some donors, it appears no sensitive financial information has been published. The donor lists themselves are limited, with one focused specifically on donors in the Washington, D.C. area who had given more than $1,000 to the DCC in previous years.

At JHS fundraisers, tech lobbyists like O’Neill rubbed elbows with their colleagues at the Podesta Group and Ogilvy, and had opportunities to meet influential members of Congress and their staffers.

In December, JHS co-hosted a holiday party with Representatives Lois Frankel and Debbie Dingell. DNC chair Debbie Wasserman Schultz attended the party, Politico reports, along with Pelosi and other Democratic leaders. The group also hosted a party for Democratic Congresswomen in July 2015.

O’Neill’s Facebook connections helped her bulk up JHS leadership, the roster indicates. A Facebook colleague who manages the company’s political super PAC is listed as the group’s treasurer, and a Facebook employee who works on outreach to politicians is also listed as a member. Senior lobbyists at Yahoo and Apple are also listed as recruits and members of the group.

“Facebook employees may participate in personal political activities, on their own time and with their own funds. Employees must keep such activity separate from work and never represent that such activities are being conducted on behalf of Facebook,” a Facebook spokesperson said about JHS.

Guccifer 2.0 posted the roster and other documents he or she reportedly took from the DNC on a personal website, and promised more documents in the future. The name is an homage to the Romanian hacker Marcel Lehel Lazar, who went by the moniker Guccifer and was responsible for hacks of several high-profile political figures. He reached a plea agreement with the U.S. prosecutors in May.

“The main part of the papers, thousands of files and mails, I gave to Wikileaks. They will publish them soon,” Guccifer 2.0 wrote on the site.

This story has been updated with comment from Facebook.