Maybe filling a disk or flooding a network connection as in

    yes | ssh server "cat > /dev/null" 

But yes take arguments so there might be more use cases:

    $ man yes
    NAME
           yes - output a string repeatedly until killed
    
    SYNOPSIS
           yes [STRING]...
           yes OPTION
    
    DESCRIPTION
           Repeatedly output a line with all specified STRING(s), or 'y'.