Ever noticed the 'd' key on the keyboard is just beside the 's' key?
I do, very often...
echo "alias lsd='echo \"You start tripping out\"'" >> ~/.bashrc
Thank me later.
spoiler
Sometimes my space key doesn't register. So when I type ls d, it comes out lsd, which normally throws back a 'command not found'. But it looks like your alias assignment fixes that in an entertaining manner.
spoiler
lol. I didn't read the first sentence of your toot. Now I think you meant that folks might try to type just 'ls' and accidentally hit the d-key also. 
@Pat Yes, that happens to me very often when I'm quickly moving through the file system.
Today I had an epiphany and added this line to the bashrc of the server on which I work.
I just hope my boss never makes my same mistake, or I'll owe him a beer I guess...
>"I just hope my boss never makes my same mistake, or I'll owe him a beer I guess..."
...or a hit of acid. 
@Pat hahaha, yes
It's unfortunate I wasn't hired in another position in which I would have worked with psychedelics, that would have taken this to a whole new level
I probably would have developed some software with that name ;)
@Pat What do you mean by spaced out?