An Instagram account belonging to cybersecurity entrepreneur John McAfee posted a plain image of the letter “Q,” an obvious reference to the “QAnon” conspiracy theory, on Wednesday minutes after it was reported by multiple news organizations that Mr McAfee had been found dead by suicide in his Spanish prison cell. The post, which depicts a black, capital-letter “Q” on a white background, went up less than a half hour after English-language news services began reporting Mr McAfee’s death. Mr McAfee’s death came after he received the news Wednesday that his extradition to the US had been granted, where he was set to face charges of tax evasion.