A while ago, a client I work for decided after a lot of discussions to finally drop support for IE11. Hurray!
Later, they decided to a show a nice page with an explanation to anyone who might still be using IE11 and encourage them to download a more modern browser.
But because we dropped support a while ago, we didn't test in IE11 anymore, and so any page we tried to load didn't work. Trying to make the pages work would be a waste of time, because in time they might stop working again.
So we decided to redirect all IE11 users to a simple static page.
Let's say you are following a guide on the internet and it provides a command for installing a package.
sudo apt install package
Without a second thought, you copy the command and quickly paste it in your terminal. Now imagine there was a different command in your clipboard, like this one:
sudo rm -rf /*do not actually run this command!
This command forcefully and recursively deletes all your files and folders starting from the root directory. If you paste text containing a newline character in your terminal, it will automatically be executed. If your terminal has elevated permissions, because you already executed a sudo command in the same session, it will not ask for your password.