BDSM stands for bondage and discipline, domination and submission, and sadomasochism in the context of sexual intercourse or “sex acts”.
BDSMers and BDSM
BDSM fans often fail to distinguish between BDSM and everyday sex.
Often while having sex, a woman will ask a man to be more rough if he is not dominant enough. This does not seem to happen to some women while on MDMA according to a thread on Bluelight.com. Perhaps because women then are forced to experience empathy, and realize that it's not always fun for her partner to be a cold tyrant all of the God damn time.
Sex and BDSM
In theory, sex is just about procreation and getting your rocks off, in which case BDSM is a wee bit elaborate.
BDSM is also unnatural. Taking out whips, “caring for your sub after spanking”, paraphernalia, tying etc. takes a lot of time and makes sex this big long dramatic act, something that is pretty much never seen in any other animal species. Despite the fact that male animals often exert force on female animals, it isn't this stageplay that BDSM becomes.
The law and BDSM
Consensual BDSM acts are semi-legal in the United States and engaging in it carries extra risk of diminishing ones legal rights as a free person. It is actually illegal to cause consensual harm to someone in the US. And many BDSM sex acts involve consensual harm.
Doe v. Rector and Visitors of George Mason University
In this court case, a student argued that a public university violated due process and free speech by banning him from school due to him having BDSM sex with a woman, that the woman later regretted.
The court ruled that BDSM was not protected under the constitution, and thus that BDSM sex is not a protected in the same way other sex acts are.
The precedent set by this ruling is that any US state or state organization can ban BDSM and not violate the constitution in the eyes of the court.