I did an investigation into what was being stored on my computer.
I was surprised at what I found: webcam videos of turkeys, advertisements for HIV drugs, other webcam videos, and an image from Saidit.net.
This is on a Linux Mint computer, but regardless of your operating system, your device is probably doing the same thing. I welcome you to watch and see what was stored on my computer....
http://john1126.com/share/Firefox-caches-advertisements-and-webcam-video-can-be-seen-offline.mp4
This is not limited to web browsers, but apps
like WhatsApp also save videos and images which can be seen offline.
Android has settings that prevent you from viewing this stored content. But law enforcement officers
or hackers could see this stuff.