The labor board may well have done nothing if Amazon had fired them for activism. But they fired them once they did start bringing up labor issues:
> Amazon has fired two employees and asked a third not to return to work, after the group organized a virtual event for warehouse employees to speak to tech workers at the company about its workplace conditions and coronavirus response.
> The two employees who were fired on Friday, Maren Costa and Emily Cunningham, had in late March circulated a petition on internal email lists that called on Amazon to expand sick leave, hazard pay and child care for warehouse workers. The petition also asked Amazon to temporarily shut down facilities where workers were confirmed to have the virus so the facilities could be sterilized.
https://www.nytimes.com/2020/04/14/business/stock-market-cov...