I am going to guess the apology is because you are already taken. Personally, I believe that most of the women that appear here are in the same status. The internet should reflect what is in real life, especially in this sense.
I believe that every woman is attached unless they say otherwise. It is simpler that way. That does not mean that you can not talk to them. I mean, you are not going to be climbing into bed with someone you are talking to on the internet. I think that a lot of the ladies miss the banter that they had when they were single or unattached. Which if in real life happened would lead one to believe that they were single, available, and most likely looking. On the net though, is a different story, when communicating. You can banter and not feel guilty about it. Once again, what would you do afterwards? I suspect that it is a mixed blessing. The ladies get to interact with the men (and likewise in reverse) replacing something that was fun and is now missed in life. At the same time they feel the responsibility of telling one that they are not (to be faithful to the one they do love). So it presents a dilemma, "Do I tell or not?"
I see this in many occasions here and a lot of the guys just assume that it is the status of "unattached". Not being corrected allows it to continue. In real life this would be considered to be the come on. In virtual life no such thing can be assumed. So I wonder what you are apologizing for? Because others communicated with you? Or because at the onset you did not say? How does that reflect upon the real as opposed to the virtual life? Does it mean we are developing new social interactions and rules that go with them? In my own viewpoint you have done nothing wrong and so need not make apologies. You can not take on the responsibility of how everyone else on the internet sees and thinks.
Just my thoughts...