I happen to have friends who work in the mental health field and I also did some consulting with some organizations focused on counseling, so I was very careful when choosing my therapist and I had no qualms asking them about their affiliations and if they knew some of the people I was close with or had worked with previously.

There were a couple of therapists who I really liked, but decided not to work with based upon some potential connections. While it may have turned out alright and while I likely would have trusted their discretion, it wasn't a risk I was willing to take.

Someone once told me to "interview" a few therapists before settling on one. It worked well for me, but did take some extra time (well worth it in the end). You could tell them about what happened before, ask them if they may find themselves in similar circumstances, and vet them. In the end, trust your gut when making the decision.