The founder of Barstool Sports, a popular blogging company, has threatened via twitter to fire employees who engage in unionization efforts. David Portnoy wrote in a tweet to employees who may be interested in organizing a union, "I'll fire you on the spot." His tweet has received backlash from New York state labor regulators, Democrat Alexandria Ocasio-Cortez, and the AFL-CIO. Each entity has responded, reminding Portnoy that anti-union behavior is unlawful and that all employees legally have the right to engage in collective action and union organizing.
See "Barstool Sports' founder says he'll fire unionizing workers--labor officials say "no way"", Aimee Picchi, CBS News, August 14, 2019