How to save full sized protected copy of thumbnail image from website

Some sites use cryptographic hash of browser request to protect saving full-sized images.

In websites like Instagram, where the website allows browser to scale the thumbnails to fill as much of the screen as possible, this limitation can be circumvented by zooming in and then opening the image on another tab...

If the image is overlaid by another HTML element, one must open the developer tools and inspect the DOM (document object model) to see the correct image address. The zoom level can't be reset to lower value before the image is saved and usually there is time limit after which the hash becomes invalid.