I've never knowingly gone to see someone whom I knew, but I once saw a girl at an agency that coincidentally her second job was as the assistant from someone I did business with. From a few comments about how my day at work had gone, she quickly figured it out, and by next session she knew my life story. She didn't look me up out of malice though, it was a coincidence, and she got curious. Thankfully, she also let me know that she knew all about me . It was fine, and at first a little nice as we used actual names, and made the GFE feel more real. We had more substantive conversations. But then the lines were blurred more than we both felt comfortable with, so we stopped. Nothing bad happened, but it could have. I think it can be dangerous for both parties, so it's a situation best avoided.