evidence: On Sept. 15, Joe Biden arrived in Tampa, Fla., for a campaign event, and as he descended the stairs of the airplane, he waved. One video capturing the moment spread quickly on social media as Facebook users shared it with derisive captions suggesting Biden was waving to an empty field. However, the video truly took off when Fox News host Sean Hannity posted it to his account with the title, "This Is Real: Biden Waves To An Empty Field." [...] According to an Associated Press reporter who was there with Biden as he left the plane, the Democratic nominee was waving to a group of firefighters and personnel who were out of the frame due to the camera angle.