Dave “El Presidente” Portnoy, founder of media company Barstool Sports, says he really hates unions. Now he’s made explicit threats to fire employees who engage in union-organizing activity — which, even if Portnoy is “joking,” has drawn scrutiny of what would represent violations of federal labor laws.

Portnoy, who sold majority control of Barstool to Peter Chernin’s Chernin Group in 2016, has a history of unapologetically attacking critics and rivals.

On Monday, he tweeted that he had heard employees of Bill Simmons’ The Ringer wanted to unionize, and included a link to his four-year-old rant on Barstool in the wake of Gawker writers unionizing about how he hoped his company’s employees would follow suit “just so I can smash their little union to smithereens.”

That elicited a reply from Live Science staff writer Rafi Letzter, who offered to provide Barstool workers info on the unionization process and explain “how little power your boss has to stop you.” Live Science’s staff is represented by the Writers Guild of America East.

On Tuesday, Portnoy said he would fire anyone who attempted to contact Letzter. In response to another commenter, who claimed to be a lawyer offering pro-bono assistance to Barstool employees wanting to unionize, Portnoy wrote, “Anybody who hires this lawyer will be fired immediately and I will personally sue you for damages and back wages.”

If you work for @barstoolsports and DM this man I will fire you on the spot https://t.co/u9vG3VgfV1 — Dave Portnoy (@stoolpresidente) August 13, 2019

According to the National Labor Relations Board, it is unlawful for employers to discourage (or encourage, for that matter) union activities or sympathies “by discrimination in regard to hire or tenure of employment or any term or condition of employment.” For example, the NLRB says, companies are prohibited from laying off or disciplining employees because they are pro-union.

Reps for Barstool Sports and Chernin Group did not respond to requests for comment.

Is Portnoy making a “joke” with the union-busting rhetoric, or is he in fact trying to discourage Barstool staffers from contemplating taking any steps to join a union? Even if it’s just an attempt to troll company critics, make no mistake: Barstool Sports management really doesn’t want its workers to unionize.

Not everyone found Portnoy’s comments funny. Rep. Alexandria Ocasio-Cortez (D-N.Y.), quoted Portnoy’s comment about firing pro-union employees and tweeted Tuesday, “If you’re a boss tweeting firing threats to employees trying to unionize, you are likely breaking the law &can be sued,in your words, ‘on the spot.’ ALL workers in the US have the protected freedom to organize for better conditions.” Portnoy remained defiant, replying to Ocasio-Cortez, “Hey @aoc welcome to thunder dome. Debate me” (as if there were something to debate about someone saying they’re willing and ready to break the law).

The New York State Department of Labor also weighed in on Portnoy’s comments, noting in a tweet that it’s illegal “to take any unfavorable action,” including termination, against employees for union-related activities under the National Labor Relations Act. “New York is a proud union state,” the department said. “We say no way, no how to intimidation, threats and union busting.”

Portnoy retweeted several posts pointing out that firing workers who are trying to unionize breaks U.S. labor laws. In response to one commenter who expressed hope that Barstool employees will form a union, Portnoy said, “Me too. Just so I can crush it and reassert my dominance.”

A few Barstool employees played Portnoy’s threats for comedy. Barstool writer and podcast host Kate Mannion posted a story on the site Monday facetiously claiming she was organizing a union at the company and included a list of mock demands, like a “small, decorative tree in the ladies bathroom for ambiance, along with a couple shelves for our toiletries/curling irons/straighteners.”

Meanwhile, other workers in digital media have fought hard for union representation, seeking job protections and other employer guarantees.

The WGA East began organizing workers in the digital sector a few years ago, starting in 2015 with the now-defunct Gawker Media. The Guild now represents staffs at companies including Vox Media — which clinched a three-year contract with the company in June after a marathon negotiating session — as well as Fast Company, Talking Points Memo, ThinkProgress, HuffPost, The Intercept, Vice Media, Salon, Slate, CBSN, Refinery29, Thrillist, The Dodo and G/O Media (the former Gizmodo Media Group).

Barstool’s employment contracts have required staffers to affirm they will not object to “offensive speech,” including conduct and speech that “openly and explicitly relates to sex, as well as race, sexual orientation, gender, national origin, religion, disability and age.” When the employment contract came to light two years ago, Barstool CEO Erika Nardini defended the policy, saying in a statement that “Barstool creates really unique comedy and the nature of that comedy means that we can sometimes easily offend.” According to Nardini, who joined the company in 2016, the purpose of the contract was to ensure everyone who works at the company is “comfortable.”