"Sexcrime" is a term used in George Orwell's novel 1984. In the totalitarian world of the novel, sex for purposes other than procreation is forbidden. The authorities repress libido in order to strengthen political loyalty.
Pynchon wrote a forward to a recent edition of 1984.
This is another reference to King Kong, specifically a scene where Fay Wray's character, an actress, is instructed by Robert Armstrong's character Carl Denham, a film director, to look up and show fear for a screentest. She is so caught up in the moment that she actually faints.
The Wounded Knee massacre took place on December 29, 1890, near Wounded Knee Creek on the Lakota Pine Ridge Indian Reservation, South Dakota. A detachment of the U.S. 7th Cavalry Regiment intercepted Spotted Elk's band of Lakota Indians and marched them to the creek before making camp. The rest of the regiment arrived and set up Hotchkiss guns around the camp.
When the U.S. troops attempted to disarm the Lakota, at least one was reluctant to part with his rifle. The situation rapidly escalated, and the U.S. troops ended up firing on the Lakota indiscriminately, killing men, women and children. At least 150 were killed and a further 51 were wounded, though some estimates put the death toll at 300. 25 U.S. troopers were also killed, with 39 wounded.