The New York Post has a story about a UFO flying by Air Force One at LAX. They have photos of something passing a large multiengine jet that is not Air Force One.
The pictured aircraft appears to be the military equivalent of a DC-10 called a KC-10 operated as a refueling tanker. I am unaware of any use of this aircraft as Air Force One.
You would hope the Post would run this story past someone with an interest in, and knowledge of, aircraft before printing it. Obviously that was not the case.
If these "amateur plane trackers" can mistake a KC-10 for a 747, they don't know much and I'd be skeptical of their UFO claim too.