Clio Chang in The New Republic:
This thought experiment, devised by philosopher Philippa Foot in 1967, along with its sadder partner dilemma, the Fat Man (instead of flipping a switch, you have to push a fat man off of a bridge to stop the trolley from hitting the five people), has found a resurgence in 2016, becoming what Brian Feldman has termed the “Internet’s Most Philosophical Meme.” The Facebook page Trolley Problem Memeshas grown to over 170,000 likes since its inception earlier this year; newly added memes attract thousands of likes and hundreds of in-depth comments (the inside joke “multi-track drifting” almost always inevitably comes up, which riffs off of another meme, the gory details of which are way beyond the scope of this piece). You can now buy t-shirts that say “I pulled the lever” or “I choose you to be my ethical dilemma” with a picture of the trolley on it. If something happened this year, you can bet that there is a trolley problem for it.
More here.