If one is going through the hassle of joining a video call on a different device to then scan it with their smartphone, all to just connect with another person, you could reasonably assume that they're friends.
Maybe if there's a "celebrity" that displays it on a live stream, that's a bigger issue, but there could be other mechanisms to dissuade this behaviour. Perhaps you could only add one friend with one QR code.
alt Hacker News
If one is going through the hassle of joining a video call on a different device to then scan it with their smartphone, all to just connect with another person, you could reasonably assume that they're friends.
Maybe if there's a "celebrity" that displays it on a live stream, that's a bigger issue, but there could be other mechanisms to dissuade this behaviour. Perhaps you could only add one friend with one QR code.