I don't understand - many people who seem technology aware sound surprised to discover that anything published digitally can't be unpublished. My friends and I

I don't understand - many people who seem technology aware sound surprised to discover that anything published digitally can't be unpublished. My friends and I were already aware of this when messing around on the school LAN in the 80s. I'm quite happy using Facebook because I only publish what I'm happy to publish. Generally, I dislike being monitored but I assume it's happening and expect my government to provide protection. The web is changing but only in the sense that it's evolved rapidly since it was created (only some 25 years ago). In the future, the web will look different while being exactly the same: people will be using it to communicate.