The Bandwidth Drain
Ubuntu Linux allows you to customize your desktop experience extensively. Some third-party customization tools, desktop environments (like specific KDE Plasma widgets), or dynamic wallpaper applications are designed to automatically download new, high-resolution background images from the internet every few hours to keep your desktop looking fresh. While visually pleasing, these automated fetches pull multi-megabyte image files constantly. If you are tethered to a mobile hotspot with a strict data cap, or working on a highly restricted corporate network, this silent, automatic downloading of wallpapers can quickly consume your bandwidth and trigger network security alerts.
Disabling Dynamic Fetching
To protect your data allowance and stop Ubuntu from automatically downloading wallpapers and background images from external servers, you must disable the specific dynamic background utilities.
Standard GNOME (the default Ubuntu desktop) does not download wallpapers from the internet by default; it only cycles through local files. If your system is downloading images, you have a specific app running. Look at your top panel for icons relating to wallpaper managers like Variety, Wonderwall, or Bing Wallpaper. Click the icon and select Preferences or Settings. Look for a toggle that says Automatically change wallpaper or Download new images and turn it Off. If you are using KDE Plasma and have a “Picture of the Day” widget active on your desktop, right-click the desktop, select Configure Desktop and Wallpaper, and change the “Wallpaper type” dropdown from “Picture of the Day” back to a standard Image or Color.