Local player should be able to see when users are spectating them (and how many)

[peppy]

and potentially list the users somewhere, similar to stable.

Discussed in #21929

^{Originally posted by poettig December 29, 2022}
In Stable, it is shown in the upper left corner who is currently spectating you. In Lazer, this is missing (or I am overlooking something).

Is this on purpose or just "not implemented yet"? If the former, what is the reasoning?

IMO this would be a good "default on, but can be disabled in options" feature.

• Implement spectator list display #31526
• Show spectating users during gameplay #31527
• Notify users of who is spectating them osu-server-spectator#259