The National Labor Relations Board (NLRB or Board) recently held that Tesla Inc. and CEO Elon Musk violated the National Labor Relations Act (NLRA) by infringing on employees’ protected rights through a tweet, and through an overly-broad confidentiality agreement employees were required to sign.

Musk’s tweet, posted on May 20, 2018 read:

“Nothing stopping Tesla team at our car plant from voting union. Could do so tmrw if they wanted. But why pay union dues & give up stock options for nothing? Our safety record is 2X better than when plant was UAW & everybody already gets healthcare.”

The Board found that in just under 280 characters—the limit of a tweet—Musk unlawfully threatened employees in “a manner viewable by the public without any limitations.” The Board considered that the tweet was posted via Musk’s personal account, which at the time, had a reach of approximately 23,000,000 followers, and that the tweet was republished and disseminated by radio, television and newspaper. To remedy the CEO’s unlawful act, the Board ordered Musk to remove the tweet, and ordered Tesla to post a notice in all its facilities nationwide addressing the unlawful act.

The Board also found that Tesla’s media contact provision, included in an employee confidentiality agreement, was too broad and infringed on protected activities. That provision told employees that “it is never OK to communicate with the media or someone closely related to the media about Tesla, unless you have been specifically authorized in writing to do so.” Applying the Boeing standard, the Board found that employees would not reasonably interpret the media contact provision, as written, to apply only to communications with the media regarding confidential information. Instead, employees could reasonably interpret the provision to apply to communications involving working conditions, labor disputes, or other terms and conditions of employment. The fact that the provision was accompanied by a general statement that the confidentiality agreement was created in response to recent leaks of confidential Tesla information was of no consequence, the Board held, because it did not change the meaning of the plain language of the media-contact provision.