Why would they know? Why would you tell them if you are afraid of them knowing? I don't think a client who looks up a public profile is doing anything wrong. But I also don't know why it would need to be discussed with the therapist you hire. And if they got angry over such a thing, then I think it would be good to know so you can get rid of the angry one and find a therapist who is less of an assholic jerk.