Wow, kuddos to RustDesk for the default warning on top their website! 
TeamViewer and other remote software should do this also
"WARNING: YOU MAY BE BEING SCAMMED!
If you are on the phone with someone you DON'T know AND TRUST who has asked you to install RustDesk,
do not install and hang up immediately.
They are likely a scammer trying to steal your money or other private information."
Even on their Git download page 😀
@stux I have a couple of usability problems with it.
First, I can't make it scale the image of the remote desktop it is displaying, so I need to scroll the window, in order to reach various parts of that desktop. Yes, I've tried playing with the Display options - to no avail.
Second, the muting setting doesn't seem to work, either. As a rule, I connect to the remote user via Skype/Teams, tell her to start the server (it is not running by default) and use the shared screen to see the password and log in. After I connect via RustDesk, when we talk, I hear myself twice - once via Skype/Teams and once via RustDesk - which is annoying.
stux⚡
VessOnSecurity