Red Hat is to some extent protected from acquisition by the ideological poison pill. Because there's no IP (open source), the value of the company is basically

Red Hat is to some extent protected from acquisition by the ideological poison pill. Because there's no IP (open source), the value of the company is basically the engineering talent, which enables the level of service Red Hat provides. Many of those engineers have very strong opinions about FOSS. The second a Microsoft (or worse, an Oracle) tried to acquire Red Hat, a huge portion of that talent would walk out the door.