US Labor Board prosecutors accused Amazon.com Inc. of imposing illegal secrecy rules on its staff, which could ultimately force the company to change its confidentiality rules.

In a Monday complaint, the National Labor Relations Board’s Seattle regional director wrote that Amazon violated federal law when it required a worker on its drone program to sign a confidentiality agreement as a condition of employment. The agreement prohibited the sharing of “business and financial information” as well as information about the company’s “techniques, technology, practices, operations and methods” — even if it’s not marked as confidential, according to the filing.

The complaint, filed on behalf of the labor board’s general counsel, accused Amazon of violating rights guaranteed under federal workplace law, and said that this affects employees at all of the company’s locations in the US.

Amazon spokespeople didn’t immediately respond to a request for comment.

Federal labor law protects the right of workers, with or without a union, to communicate with each other about their working conditions. NLRB members in Washington, where Democrats hold a majority, voted in August to establish a new standard making it harder for companies to defend workplace handbook rules that agency officials contend could have a chilling effect on workers’ rights.

Complaints filed by regional directors of the NLRB are considered by agency judges, whose rulings can be appealed to labor board members in DC, and from there into federal court. The agency lacks authority to impose punitive damages on companies or hold executives liable for violations, but can require companies to change policies deemed to violate the law.

Cheddi Skeete, the former drone project manager who originally brought the case to the NLRB, said in an interview that he was concerned about how overly broad confidentiality clauses make it difficult for workers to network and job-hunt for fear of getting in trouble with their existing employers.

Skeete, who filed a separate discrimination and retaliation case against Amazon earlier this year, said he hopes the NLRB will help ensure a reasonable balance between companies’ need for privacy and employees’ need to be able to discuss their work. “This could be a game changer in the tech world, and in the corporate world,” he said.