Last year, Elon Musk tweeted “Use Signal,” leading to a spike in new users. Twitter’s lawyers said in a footnote in a previous filing that Musk had been messaging with investor Marc Andreessen of a16z on Signal about a Twitter investment. The problem for Twitter’s discovery process is that Signal messages can be set to auto-delete; Musk’s lawyers maintain he doesn’t ordinarily use Signal for business. Now, there’s a sealed motion that.... contains Musk’s Signal tweet. 👀