The Young Turks Network has the article MSNBC Fires Sam Seder Over Alt-Right Smear Job.
This was the quickest way for me to learn what this is all about.
If twitter would have given him the space, Sam Seder should have used my technique. I now use <sarcasm></sarcasm> flags around all my posted sarcastic remarks so that nobody can misconstrue them.
In plain text, it would have looked like the following:
<sarcasm>Dont care re Polanski, but i hope if my daughter is ever raped it is by an older truly talented man w/ a great sense of mise en scene</sarcasm>