also endorsed by then-Democratic presidential candidate Senator Bernie Sanders. The union received pushback with a letter from Burgerville's CEO, Jeff Harvey, being distributed to workers discouraging them from joining the union. In June 2017, Burgerville paid a settlement of $10,000 after an investigation by the Oregon Bureau of Labor and Industries, which found that the company had violated state-mandated break periods for workers. In April and May 2018 the IWW won NLRB elections in 2 Burgerville Locations. In August 2016, workers at Ellen's Stardust Diner in Manhattan formed Stardust Family United (SFU) under the IWW, driven by the firing of thirty employees, as well as an unpopular new scheduling system. After going public, the union accused Stardust management of retaliatory firings and posting anti-union materials in the restaurant. On September 9, 2016, the 45th anniversary of the Attica Prison Riots, 900 incarcerated workers organized by the IWW and many other prisoners participated in the 9/9 National Prison Strike declared by the IWW's Incarcerated Workers Organizing Committee. Supported by a number of anti-incarceration and prisoners' organizations such as the Free Alabama Movement, the strike focused on the poor conditions in many American prisons and the low rates of prisoner pay for maintaining prisons and engaging in commercial production of goods for third-party companies. The strike affected an estimated twenty prisons in eleven states and was strongest at the William C. Holman Correctional Facility in Alabama. Estimates of the number of inmates affected range from 20,000, to 50,000, to as high as 72,000, with David Fathi of the ACLU National Prison Project judging it to be the "largest prisoner strike in recent memory". Initial media coverage was slow, with strike organizers complaining of a "mainstream-media blackout", which could be attributed to the difficulty in communicating with prisoners, as many prisons went on lockdown either in response to prisoner strike activity or in anticipation of it. Organizing during COVID-19 pandemic The IWW also organized workers during the COVID-19 pandemic in the United States. In May 2020 the IWW established the Voodoo Doughnut Workers Union (DWU) in Portland. The newly formed union delivered a letter to management announcing the formation of a union and demanding higher wages, safety improvements and severance packages for employees laid off because of the coronavirus and Oregon's ongoing "shelter-in-place" order. In February 2021, after months of organizing, DWU workers officially filed for a union certification election with the National