While it's not exactly my cup of tea, I wouldn't condemn people for being into it and/or taking part in it so long as it doesn't harm somebody else.
One proverb that I live by is quite simple: Live and let live: You should tolerate the the opinions and behavior of others so that they will similarly tolerate your own.
If they're not doing anything to hurt or harm someone else, why should it be any business to others what they're into? Everyone has some 'unusual' kink in the eyes of another. This will not be the first of them, nor will it be the last and I don't believe that it would make them any less of a person than anyone else. Don't worry about the people with different personal views than your own, worry about people who's actually going out of their way to murder innocents. I think that deserves more concern than how individuals choose spend their personal business. Of course, this is my personal thoughts on the topic.