Yep. Also we might know of it from someone else. But I've been called a liar and a barebacker after being the 2nd person confirming this WG being a barebacker and she is not even a forum's favourite WG. Imagine if I shared this kind of information about some of the well reviewed ones. 
I was among those who assumed you'd barebacked her after your initial post in the thread. But what do you think people will believe when you make claims as boldly as you did?
You said you know for a fact she does it, so the obvious conclusion is that you that did it otherwise that 100% certainty cannot exist. The alternative holds little more credibility than the stories you get told by someone who heard it from a bloke down the pub.
Then you said you'd confirm the story via PM to people you trust. I didn't bother getting in touch, because you have no more reason to trust me than I do you.
Now you say you know of loads of others who offer it under the counter but won't say who. Again, what conclusion are we supposed to jump to on hearing that?
The last thing I want to do is piss anyone off, and if you've taken offence to anything I've said anywhere in the thread, I apologise. Although I don't know you from Adam, some of the other comments in the thread seem to back up your assertion that what you say has some credibility around here. But surely you can see how things would look to someone like me who doesn't know you?