Clicking on the much larger links in the email to “sign on” or “add your name” took the recipient to a petition. At the very bottom, in small, light grey text, was the disclosure that revealed the petition was paid for by a range of politicians and organizations that include 20 current Democratic House members, one primary challenger to a sitting House Democrat, two candidates for the Democratic nomination in Georgia’s 7th District, two other House candidates, one mayoral candidate, a state auditor, PACs, a progressive digital firm, and what appears to be a custom trophy manufacturing business based in Massachusetts.

In another example, California Rep. Linda Sanchez on Monday told her list that she needed 100,000 “original Citizen Co-Sponsors of the Medicare for All bill” for it to pass. Besides Sanchez’s own campaign committee, 16 other candidates and organizations paid for the petition, including activist networks such as Left Action and Kos Media, LLC.

Each of the groups sponsoring the petition can send it to their email subscribers. When one of those subscribers signs the petition, his or her name can be shared with another group on the petition. The digital teams running the petition make sure every sponsoring organization that got one of their subscribers to sign the petition also gets a new name — who signed up through someone else’s list — in return.

Trading and selling

Joint action emails are not the only way people start receiving emails from lists they didn’t sign up for. Candidates can also swap names.

They’re not trading actual names; they’re trading email addresses of equal value. That means that if one campaign is handing over a bucket of names of people who have donated in the last 60 days, they need to receive from the other campaign names of people who have also donated in the last 60 days. An even exchange doesn’t have be reported as an in-kind contribution to the Federal Election Commission.