Sure, but not in an illegal way, I think its warranted. Its one thing to post the recall letter internally but to publicly bash your employer and call for the firing of others and expect to keep your job is insanity. They could have easily rewritten the letter to be less inflammatory, identified the problems, proposed solutions that did not target individual leaders and posted it on an internal board. We are at a strange time in industry where people don't think they will be fired for publicly torching their employer (see the recent Washington Post debacle). With that said, Brian's response was equally bad.
If your execs prevent your employees from interacting with the board of directors, their only option is to go public to get the board and investors' attention. Brian only wants this to stay internal because he can control the narrative, how people communicate about it, and what the board and investors are made aware of.
Now, I am no lawyer, but i am pretty sure that this would fall under "discussion of workplace conditions" - a type of speech in California protected by the labour code and not allowed to be retaliated against.
I'm not sure it's that clear cut, since they're singling out and attacking fellow employees in the process. Seems like the kind of complex labor case that would be heavily litigated.
