A very brief search can easily turn up the strangest things on the Internet.
Apparently Elvis sightings are enough of an issue that the U.S. Copyright Office felt they needed to deal specifically with it, thirty-plus years after his death. The below is taken from the U.S. government’s “What Does Copyright Protect?” FAQ:
How do I protect my sighting of Elvis?
Copyright law does not protect sightings. However, copyright law will protect your photo (or other depiction) of your sighting of Elvis. File your claim to copyright online by means of the electronic Copyright Office (eCO). Pay the fee online and attach a copy of your photo. Or, go to the Copyright Office website, fill in Form CO, print it, and mail it together with your photo and fee. For more information on registration a copyright, see SL-35. No one can lawfully use your photo of your sighting, although someone else may file his own photo of his sighting. Copyright law protects the original photograph, not the subject of the photograph.
Finally, now I know what to do with all those pictures I took in Vegas.