The founder of a notorious sports-focused website became the subject of a social media firestorm on Tuesday after posting a series of tweets criticizing efforts by workers at a competing website to unionize — statements that some people pointed out might violate labor laws.

Dave Portnoy, the founder of sports blog Barstool Sports, tweeted on Monday about a recent unionization effort at The Ringer, a sports and culture website run by former ESPN columnist Bill Simmons. Portnoy linked to a 2015 blog he wrote about Gawker Media’s unionization efforts, in which he wrote that he hopes his employees try to unionize so he can “smash their little union to smithereens.”

Rafi Letzter, a staff writer at Live Science, responded: “If you work for Barstool and want to have a private chat about the unionization process ... my DMs are open.” Portnoy retweeted the reply and added that he would fire any of his employees “on the spot” who direct messaged Letzter.

Many digital media newsrooms have unionized in recent years including Vice, Vox, HuffPost and BuzzFeed News. While these unions have generally been recognized, it has not been without difficulty. In 2017, DNAinfo and Gothamist were abruptly shut down by their billionaire owner Joe Ricketts after they unionized.

This year, unionized employees in two newsrooms walked-off the job: Vox employees walked out during their bargaining process to send a collective message to management to take their demands more seriously, and BuzzFeed News workers did the same amid a months-long standoff with management over their union’s voluntary recognition.

Portnoy's tweets, which garnered backlash from some in digital media and support from many Barstool readers, caught the attention of The New York State Department of Labor, which chimed in, tweeting, “It is illegal to take any unfavorable action — including termination — against employees for union-related activities under the National Labor Relations Act.”

The department asked that anyone who is being denied wages or retaliated against contact their office, writing, "We say no way, no how to intimidation, threats and union busting."

Rep. Alexandria Ocasio-Cortez, D-N.Y., added her perspective, tweeting, “If you’re a boss tweeting firing threats to employees trying to unionize, you are likely breaking the law.”

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.



See @NLRB &union orgs like @AFLCIO for tips. https://t.co/bU7WlHrp1d — Alexandria Ocasio-Cortez (@AOC) August 13, 2019

In response, Portnoy challenged the freshman congresswoman to a debate.

Barstool Sports emerged in recent years as one of the most successful — and controversial — sports-focused websites on the internet. Portnoy has often been the subject of critics who say he's a misogynist, citing his previous statements about female sports journalists.

Portnoy’s union tweets come after an editor of the conservative politics website The Federalist made a similar threat. In June, Ben Domenech, co-founder of The Federalist and husband of Meghan McCain, tweeted: “FYI @fdrlst first one of you tries to unionize I swear I’ll send you back to the salt mine.”

FYI @fdrlst first one of you tries to unionize I swear I'll send you back to the salt mine — Ben Domenech (@bdomenech) June 7, 2019

NBC News was unable to reach to reach Portnoy for comment. Letzter said his offer still stands.

“If anyone working in digital media wants to hear about how they can start a union, they should feel free to email me,” he told NBC News in a direct message on Twitter.