National Law Review on Limits on Employers

Employers are not allowed to create the impression of surveillance of union organizing activities, even if such surveillance isn’t actually happening:

“One of the more nuanced, subtle violations occur when it comes to management surveillance of worker union activity. Aside from actual spying, many companies do not realize the NLRA also prohibits an employer from “creating the impression” it is surveilling employee unionizing efforts. For such a violation to occur, an employer need not actually spy (e.g., sit outside a union hall and monitor which of its employees attend a meeting). Rather, it is sufficient, for example, for a manager to make remarks to employees that would lead the workers to believe the employer is surveilling their activities (even if no spying in fact occurred).”

https://www.natlawreview.com/article/does-creating-impression-surveillance-violate-labor-law