Following the tragic news that Patrick Day has died four days after a fight with injuries suffered in the fight: https://www.bbc.co.uk/sport/boxing/50066825
Why do we still allow boxing to be a recognized sport?
BTW on the users' profile page you can see that the reputation comes from the association bonus.
I am not sure, perhaps from SEDE it is possible to get other sites for a given account. However, I haven't done any query which runs across multiple sites, so I would not be able to create such query in short time.
If you go to your profile (on any site) and click on "Edit profile and settings" and "Hide communities", you can see there a brief description of what it does.
> Choose which communities will appear in the Communities and Top Network Posts sections of your profile
> Hiding a community means other users will not see it in your Communities list or Top Network Posts. It does not, however, mean your activity is private.
> New sites that you join will be linked to your other communities by default.
The part which is there shown in bold basically says that if I check users' activity in the network profile, then I see also the activity in the hidden communities. (But I have to get the link to network profile from somewhere - it is not shown in profile on a site which is among hidden communities.)
Of course, the question is whether the article is reliable - but maybe somebody could write an answer based on that. (Or at least start a CW answer - where additional information can be added by other users, if they manage to find something.)