A 21-year-old recent college graduate was behind an anonymous website that put out widely shared fake election polling in Wisconsin, Nevada and California, the Guardian can reveal.

The website, Median Strategies, abruptly shut down and withdrew its polling earlier this week following questions from a reporter from the Los Angeles Times. In an unsigned statement, it described a “short-term social experiment” to examine how fake polling “could enter and spread through the political information ecosystem without independent verification”.

“I wanted to see if fake polls could really penetrate the ecosystem that easily,” Rahil Prakash told the Guardian on Thursday when reached by phone. “And as it turned out, it could.”

Karen Bass, the mayor of Los Angeles, touted Median polling data after it appeared to put her ahead of her election challenger by more than 10 percentage points. The poll was also cited by the California Post. A widely followed polling aggregator on X also shared the group’s Nevada poll, although several credible polling organizations did not aggregate Median polling because they could not verify its methodology.