American automaker Tesla Inc. seemed to have caught the National Relations Board’s (NLRB) attention as the US labor law enforcer files a complaint against the auto company for unfair labor practices.

The federal agency issued the complaint after verifying that the company has violated workers’ rights by prohibiting their employees from leafleting or even talking about their working situations and safety issues at Tesla’s flagship factory in Fremont, California.

The charge additionally claims that the workers in Fremont were questioned by the management over protected union activities.