My questions are:

• Does the DuckDuckGo Firefox extension "Privacy Essentials" add a local css file to every visited site?
• Can others reproduce this?
• Is this harmfull or not?

Background:

I have a simple static one page site with just one html and css file. It's completely tracker free. Debugging it a bit with developer mode (F12) on I discovered a second css file. This file isnt on my webserver but added local. To pinpoint what caused this I removed every add-on / extension in my browser one by one, reloading and checking my website every time. Took me a while because didnt expect this one causing it.

To reproduce:

• Install the extension from the link.
• Open a random site
• Check in developer mode the tab Style editor.
• Scroll and look for a file named %3Ais(%5Bid*%3D'google_ads_iframe'%5D%.css or something like that.
• Remove the extension and refresh.
• Check if the file disappears.

Content of the css file: :is([id*='google_ads_iframe'], [id*='taboola-'], .taboolaHeight, .taboola-placeholder, #credential_picker_container, #credentials-picker-container, #credential_picker_iframe, [id*='google-one-tap-iframe'], #google-one-tap-popup-container, .google-one-tap-modal-div, #amp_floatingAdDiv, #ez-content-blocker-container) { display:none!important; min-height:0!important; height:0!important; }

Edit 25-03-2024: Changed title to not give the wrong impression. See comments below.

My main question is about /run/user/1000:

• Should I avoid touching it?
• Could I delete it?
• Is there something wrong with it?

Background: I'm fairly new to Linux and just getting used to it.

I use fsearch to quickly find files (because my filenaming convention helps me to get nearly everything in mere seconds). Yesterday I decided to let it index from root and lower instead of just my home folder.

Then I got a lot of duplicate files. For example in subfolders relating to my mp3 player I even discovered my whole NextCloud 'drive' is there again: /run/user/1000/doc/by-app/org.strawberrymusicplayer.strawberry/51b78f5c/N

Searching: Looking for answers I read these, but couldnt make sense of it.

• https://unix.stackexchange.com/questions/162900/what-is-this-folder-run-user-1000
• https://forums.linuxmint.com/viewtopic.php?t=412850 So if its a bug with flatpaks I'm inclined to delete a certain db at ~/.local/share/flatpak/db

Puzzled:

• Is this folder some RAM drive so my disk doesnt show anything strange? Because this folder doesnt even show up at the root level.
• Are these even real? Because the size of it (aprox 370 GB) is even bigger then my disksize (screenshot).

Any tips about course of (in)action appreciated.

Although the headline focusses on a obvious category of media, it really can go wrong on a lot of other categories as well.