My T says that many of the conflicts people bring to therapy begin in social media, which I have nothing to do with. I see some of my middle aged friends rather attached to their phones because they want to keep in touch with extended family or the like. I could see how it might possibly be relevant or helpful depending upon the person.

Public information is available for anyone, including a T. If a client is concerned about it, s/he can bring it up or ask about the T's policy or the specifics such as have you googled me? This would seem to me to just feed into general worries about the T's perception of them, but it's up to each person to handle it as they wished.