Somewhat inspired by the menu you can view from middle-clicking a player with the Cosmetica mod (hopefully this is the right mod,)
a feature where upon middle-clicking a player you can view a menu to see a person's various cosmetics enabled.
No statistics have to be generated ofc, it's not like getting a KDR off of a player for every server they join; instead, this menu grabs the statistics of a player that can be obtained, such as previous usernames, previous skins (which could be utilized as a skin-stealer-esque feature,) owned cosmetics, perhaps Hypixel stats from their API, or other information that someone might want to share.
Also, this is not an invasion of personal information, since all of these stats can be found using various resources such as NameMC, a tool for viewing all used skins and usernames of basically anyone's minecraft account.
And of course these features should be enabled/disabled easily if someone does not want to share this information directly.