Mark Zuckerberg's old emails are seen as crucial in the antitrust trial case against Meta.Zuckerberg's early emails show his concerns about antitrust issues and the future of his expanding empire.In the emails, he discusses worries over growing competitors and the potential need to spin off other apps.During the trial, Zuckerberg was pressed on his prescient warnings about company breakups.Legal experts suggest that the government faces challenges in proving Meta's monopoly cementation through acquisitions.Zuckerberg's worries extend to acquisitions like Instagram and WhatsApp, with concerns about potential competition.The FTC alleges that Facebook bought Instagram and WhatsApp out of fear of competition and potential pivots.Zuckerberg expressed concerns about competitors like Path and Dropbox in his emails.Conversely, he seemingly admired the unambitious stance of WhatsApp's cofounder, Jan Koum.Zuckerberg also showed frustration over internal issues at Facebook, particularly regarding the development of a camera app to compete with Instagram.