It is generally regarded as a boundary crossing and discouraged. Clients get the opportunity to bring what they want to into the therapy session. When I am working with teens sometimes I check their social media to see if their public image is healthy and appropriate. Usually I do that with the client. I had a teenage client tell me they had inappropriate material on their social media page and asked me to help them delete it. But I don't feel right about googling my clients or looking them up on facebook. Besides, clients usually have one therapist while therapists have many clients. I care about my clients, but I do need to have a life outside of work and I don't need to spend extra time doing something that is not very helpful or therapeutic that I would feel that I need to keep quiet about for fear of being found out doing something that could be inappropriate.