Several times attempts have been made to start unions, and the company (Avantair) invented all sorts of false charges to use as grounds for firing those they suspected of being involved.
The first post of the thread referenced above is quite accurate, despite what many others in the thread later claim.
It's also quite true that management at Avantair reads threads in which their employees post...and punishes the employees accordingly. The thread referenced above mentions another web site, "flightinfo." Avantair fired employees for posting on that site privately.
Good companies have no need of that kind of behavior.