You might have seen the joke appear in your Twitter news feed: Someone tweets that you've just got to see this shocking controversial thing right NOW, but when you click on the link it only takes you to someone else's tweet, which says something similar ... and ... if you keep clicking ... you eventually end up at a dead link/404 page.
Hasson wanted to see just how big the chain was. So he made a program to map it. It's huge. It looks like this (click to enlarge):
If you want to see the originals in more detail, $4.
Turns out the average number of links in the chain is 18 - which is pretty impressive given that each person in the chain has to "get" the joke and change their link to the status update they originally saw it in.
Howe is no stranger to trolling. He once accused a fellow conservative of having sex with animals - which led to $4.
Hasson has offered his code to $4 - meaning it can be used, presumably, to map the virality of any tweets you want.