Trust. I have used it with @devast8a, @pilojo, @randalserrano, and a few other users. We all trust it. It's very safe, and you can end the connection at any time. PERFECTLY safe.
I have used team viewer for the past 3 years. I have never had a problem with it yet. I have helped plenty of people with it and have been helped plenty of times. I consider it one of the most trusted programs of its sort out there.