May Day Mystery

Happy May Day! It's International Workers' Day.
In 1786, the “Marriage of Figaro” premiered in Vienna.
In 1830, Mary Harris “Mother” Jones was born.
In 1886, a general strike began in the U.S., which ultimately led to the 8-hour work day.
In 1923, Joseph Heller was born (author, Catch 22).
In 1924, Terry Southern was born (screenwriter, "Dr. Strangelove").
In 1927, Harry Belafonte was born.
In 1945, Germany announced that Hitler was dead.

Now check out this crazy puzzle! Or ...what the hell is it?

And don't miss this, either. Know thy enemy and all that.