Ultimately, we are all responsible for our own saftey, and our own lives.
And guess what? STD's only recently became non-leathal. Until the advent of antibiotics, pretty much all 50 of them would either ruin your life, or take it from you after a long, drawn out illness. As it is, there are still about 20 that are non- curable. AIDS is just the latest virus to rear it's ugly head in that column. Still, even when all of them were death sentances, people didn't stop having sex. This, despite the best efforts of religion and governments to cast the activity in the worst light possible.
If the spectre of AIDS causes you so much concern that you wish to limit your sexual contact to a single person for the rest of your life, then please, by all means do so.
However, those of us who do not agree with the idea that such a limitation would be appropriate... in order to lead a happy, mentally healthy life... we should be free to do so with like minded others, and not hindered by restrictive laws and religious doctrine that seeks to rob us of that choice.
Sure, we'd be taking a risk. You take a risk every single time you get up in the morning and get behind the wheel to go to work. You take a risk going to class, that maybe one of your classmates might not flip out and start shooting. You take a risk by not getting regular checkups, or by not sticking to your diet, or by smoking, or using drugs, or eating the wrong foods, or breathing the wrong air...
Life itself has some risk. The chances you will die at some point are 100%. It's up to the individual to decide how he wants to spend the time between the cradle and the grave. Personally, and I don't think I'm alone on this, I want to spend mine close to other people whom I like, whom I love, and with whom I would like to share myself... as often as possible.
I will mitigate the risk by being knowledgable about the disease, and by taking effective steps to protect myself and my partners from exposure.
Number Two: Conform, Number Six! Conform!
Number Six: I will not be stamped, filed, indexed, briefed, debriefed, or numbered! I am a person.