Usually the medical test thing is enough to shut them up.
Anyway there are many such example arguments around the internet, just DuckDuckGo "nothing to hide". There's even a Wikipedia article about it [1].
Edit: Oh, I often give Uber's deleted posts about how they know their users had one-night stands as an example too. See [2] and [3] for one of the deleted posts.
[1] https://en.wikipedia.org/wiki/Nothing_to_hide_argument [2] https://money.cnn.com/2014/11/25/technology/uber-prostitutes... [3] https://web.archive.org/web/20140827195715/http://blog.uber....