Americans as a group seem to view ever-harsher conditions in prison and after release as being a necessary disincentive for criminal behaviour. Sexual assault in prison and its tacit support amongst the general population seems to me to just be another part of this "hang em high" mentality - how often do you hear people joking about dropping the soap or "sharing a cell with Bubba" when talking about criminals?

The fact that this sort of approach to criminality drives up recidivism does not ever seem to enter the conversation, with the possible exception of places like HN or Metafilter or other liberal-by-American-standards forums.