A federal appeals court upheld the conviction of a former Uber driver for posting death threats on Facebook.The 7th U.S. Circuit Court of Appeals last week affirmed the conviction of Mohammad Waqas Khan, unconvinced by his claims that the Facebook posts were rap-inspired hyperbole and not “true threats.”“Khan’s posts were so violent, explicit, and resolute that they constituted threats under either an objective or subjective standard. Among other macabre warnings, Khan repeatedly and categorically …