What sort of person would...
Before you finish that thought, go to Twitter and you will find all sorts of people perpetrating the crudest violations of human decency.
This is something Robin Williams' daughter Zelda has discovered since her father took his life on Monday.
Grieving for her dad, she posted a simple tweet. It was a quote from French author Antoine Saint-Exupery and then ended with "I love you. I'll miss you. I'll try to keep looking up."
You might imagine that many on the site would offer their condolences. They did. However, some thought they'd send her gruesome Photoshopped images of her father. Others decided to insult her with words.
The result is that Williams, 25, has left Twitter. She posted: "I'm sorry. I should've risen above. Deleting this from my devices for a good long time, maybe forever. Time will tell. Goodbye."
Why should she have to put up with base, pointless, cruel invasions in her grief? Why should she have to be confronted daily by those who simply want to cause her pain, with no reason other than the pleasure in causing someone anguish?
She also chose to leave Instagram. There, she wrote: "Mining our accounts for photos of dad, or judging me on the number of them is cruel and unnecessary."
It's more than that. It's inhuman.
She chose Tumblr to leave an astoundingly measured message to all those trolls who had magnified her misery.
After expressing thanks to all those who had sent her kind messages, she wrote this on her Contrariwise feed: "As for those who are sending negativity, know that some small, giggling part of him is sending a flock of pigeons to poop on your car. Right after you've had it washed."
Zelda Williams will surely find it hard to live without her dad. How can those who sent her nasty messages live with themselves?