This image was acquired from
flickr. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
people monochrome Lot Inventor Demonstrates Blackout Box. Les De Forest famous U.S. radio wizard has invented blackout box which if attached to your radio station will automatically turn out lights set off warning siren or bells when the station goes off the air during blackout. Members of the Los Angeles California Defense Council