I think it's sometimes used as an excuse on the therapist's part. If the individual is okay with the risk, I don't think it's the therapist's place to tell them not to for security reasons. If they are concerned about liability, they can have the person sign something saying they understand the risk.

Mine has never brought it up as an issue, and I don't really care. I'm not going to run for office and I haven't made criminal confessions or anything that would be damaging to my reputation. I mostly email when I'm in despair, so if someone wants to take me down over that, I don't think I'm the one that will end up looking bad.