Steam provides the ability to hide your screenshot from everyone and make it private, but Steam does not allow you to do it massively for all screenshots, and there can be many of them. Perhaps you (like me) need such a function and this script implements this.
Steam Screenshots Hider
Just hide all your screenshots in Steam, make it private easy and fast
Go to the screenshot page
Choose a sorting setting 'Your public screenshots' or 'Your friend-only screenshots' depending on where the screenshots are located
When you see your screenshots, click on the hotkey, the default is Q (you can change it, see in the code variable triggerBtn. Please note that there can only be a letter. Also pay attention to the keyboard layout, make sure that you have selected English
Wait for the page to fully scroll (this will be done automatically)
When the page scrolls, confirm in the dialog box
Next, Steam asks if you are sure that you want to do the action with screenshots, click yes
Well done! Now, your screenshots is private. Reload the page for make sure of it. Sometimes due to incorrect operation of the Steam, problems may arise in which not all screenshots will be hidden. In this case, follow the instructions several times.