Employers can ban employees from using work email for personal purposes, including union organizing, the National Labor Relations Board ruled on Monday. The board's three Trump-appointed members voted for the rule, which overturned an Obama-era rule reaching the opposite conclusion. The NLRB's lone Democratic member, Lauren McFerran, dissented from the decision.

Federal labor law protects employees' right to organize without interference from employers. That includes a limited right to engage in organizing activities in the workplace. For example, an off-duty employee has a right to distribute union literature in an employee break room or the parking lot.

Labor-rights advocates have long argued that this principle should extend to workplace email systems. They point out that email can be one of the most efficient ways for workers to contact one another and discuss workplace issues. And they note that the costs to employers from added email use is negligible.

In a 2014 decision, an Obama-appointed majority of the NLRB agreed with this logic, holding that "employee use of email for statutorily protected communications on nonworking time must presumptively be permitted by employers who have chosen to give employees access to their email systems."

But then Donald Trump got elected president and Republicans gained control over the agency. They have a different perspective on the issue.

Republicans see property rights as key

The latest ruling focuses on the casino operator Caesars Entertainment, which has broad policies prohibiting employees from using its email systems for personal use. These policies don't single out union organizing. Rather, they prohibit employees from sending "non-business information" via email or using email to solicit "for personal gain or advancement of personal views." The policy appears to ban employees from recruiting members for their church or bowling league as much as it bans union solicitation.

Still, labor organizers objected, arguing that this broad policy impinges on worker rights to communicate with one another about workplace issues. They pointed to the Obama-era rule protecting workers' rights to communicate with one another via email about workplace concerns.

But the NLRB's three-member Republican majority took the case as an opportunity to overturn that rule. For the Republican board members, employer property rights are of paramount importance in the case. Employers own their email systems, the board reasoned in its Monday decision, and they have a right to decide how it's used.

The law merely requires that workers be given some reasonable means of communicating with one another, the board held. The law already protects the rights of workers to communicate via face-to-face conversations and the distribution of literature. That gives workers sufficient opportunities to communicate to satisfy the requirements of labor law, the board ruled. In the majority's view, it wouldn't be appropriate to extend those protections to email because doing so infringes on the employers' property rights to their email systems.

The board's lone Democrat, Lauren McFerran, dissented from the ruling, arguing that the majority had misinterpreted the law. She argued that property rights weren't relevant to the case because Caesars had already granted its employees access to the email system.

And she pointed to other cases in which the NLRB or the courts had upheld workers' rights to communicate about labor issues using company property. For example, workers have a right to put union stickers on their hardhats—even if the hardhats are the property of the employer. That's because the worker already has permission to use the hardhat, and attaching a sticker doesn't interfere with the worker's ability to do his or her job. The same reasoning should apply to communicating about labor issues on a company email system, McFerran argued.