We have many users who use it in public or semi-public places. You are only interacting with your Focusmate at the start and end, and that for just 30 seconds or so to say hello and share what you're committing to work on. As compared to people having a loud conversation in a cafe, this is very, very minimal. We also have users who are in libraries or other quiet spaces, and they usually indicate that on their profiles and by logging in early and sending a chat to their partner.
As far as the "unusual nature" -- a few things. One, consider that it takes a fair bit of effort to set up and attend a Focusmate session. That screens out 99% of privacy concerns because people are truly motivated to be there to get work done. The fact that users have a profile and track record also mitigates this issue. Sure, we have new users joining, but once someone has 5-10 sessions under their belt, the community has had a chance to vet them. As far as new users with malicious intentions, that's certainly possible, and we have blocking and reporting functionality to stay on top of those issues. Last thing I'll add is that there isn't much someone can "do" to you over videoconference. If you were to feel uncomfortable, you can just close the tab.
You can learn more here: https://www.focusmate.com/community
I guess this isn't much different to any other remote conference in that regard - any thoughts on how to use this in a polite and safe way? Or is the idea it's really for use in a private environment only, like your home? That is implied in some of the intro material.
Basically, what are etiquette considerations or issues for other people who aren't involved in the session? Just don't use it in that context?
Secondly, how have you handled the unusual nature of this compared to normal conferencing - where you are directly and continuously interacting with the other person, rather than having them quietly watching over your shoulder as in this case? There are obviously quite concerning potential privacy issues here as well.