Some people have a real issue with sexuality of any form. To be honest, I feel that if no one is getting hurt and it's consensual, do what you will. There are some limits that I feel are hard and fast (unintentional puns there, sorry). Sex with children or people who are unable to give fully informed consent is wrong and reprehensible. A child does not have the capacity to make the decision to engage in sex with any sense of the long term ramifications, as a general rule. Consent derived under duress is the same as refusing to listen to denial of consent, as such, it consitutes rape. Engaging in practices that are categoricly unsafe (including various unhygenic ones) is another thing that I just won't do and I highly advise others against doing so.
Now, this said, there are ways to engage in practices that seem to be unsafe or have the potential to be unsafe. This where one needs to be responsible in choosing their partner(s) and in their exercise of the practices they're employing. Bondage can be a beautiful thing and it can also be incredibly exciting. It can also be a thing of very real horror and incredibly dangerous. The difference between the two is responsiblity and consent. Many of the practices used in the BDSM community look to be quite unsafe and horrible to the casual observer. They are generally things that are pushed away to the fringes of sexuality (no one ever breathes a word about it in any of the *college level* sexuality classes even). If you are responsible, set clear limits, and maintain open lines of communication with everyone involved, pretty much any sexual appetite you indulge is fine.
I don't know why the rest of the world doesn't seem to see it this way. Oh, there's nothing wrong with sex but it needs to be within this specific set of circumscribed rules. If you do things a different way, you're going to automaticly be morally suspect and otherwise an undesireable figure. Gods help you if you happen to actually take into account other factors such as emotions, relationships, or anything else of the real world. Suddenly, you find yourself dealing with such a mess of social sterotypes, that it's really quite ugly.
I hate the way society tries to tell me what to do in the bedroom, who to do it with, and how I should feel about it. I hate the way that society attempt to dictate to me what my interests should be and that if I fall outside of those norms, I am somehow flawed as a person and of lesser value.
I think if society at large worried more about how to empower people to take some measure of pride and a healthy acceptance of the diversity of personalities in the world, and less about putting us into boxes, we'd all be better off. Sexuality and relationships included.