I apologize for my evidently-cryptic message above. Here's a little more detail:
Geni has a somewhat-generic format for projects. They can be about anything: a project of Olympic athletes, or a project for World War 2, whatever. The format for projects includes a description that users can edit and format in wikitext, the ability to "tag" profiles in the project (e.g. Jesse Owens in an Olympic Athletes project), and discussions that are contained to the people who have joined the project.
Our users have amazed us with the myriad ways in which they've employed projects to meet a need on Geni. One such way that we officially embraced, is to create "help" projects for users from a specific country. These came to be called "country portal projects" and typically include information in the description instructing users on naming standards, use of multilingual fields on Geni, local privacy laws, etc. We felt these were helpful enough that we compiled a list of official country portal projects, and started (programmatically) recommending to new users that they follow the project corresponding to the country from which we detect they are accessing the site. You can identify the country portal projects by the gray box at the top of the description that starts with, "This is a country portal project..."
One outcome we did not anticipate, however, is that users might try to "tag" every profile from a certain country, to the portal project; for example every profile on Geni for anyone born or lived in Canada, to the Canada portal project. This poses two problems:
1. Projects can handle a LOT of tagged profiles, but not tens of millions or more. Furthermore it's just busy-work -- I know our search engine is a little inadequate at times, but the proper solution to this problem is for Geni to provide a search function for profiles in a specific country, NOT for users to have to manually tag millions of profiles to a project. (Incidentally, you CAN use our search engine to filter a name search by country; so if you wanted to find all the Windsor surnames in the UK, that's possible today).
2. Whenever a profile is tagged to a project, all project collaborators are notified of the addition. This makes sense for small projects that users choose to join (e.g. Olympic Athletes) but is confusing and a nuisance to users who clicked our prompt to join a country portal project, and are then subsequently inundated with notifications about thousands upon thousands of profiles being tagged to that project.
Consequently we changed the site to disallow tagging profiles to the official country portal projects. Per my message above, if you want to tag profiles to locality projects, we recommend creating sub-projects for individual regions, provinces, states, etc. and tagging the profiles to those. That will reduce the total number of profiles tagged to any one project, and will also eliminate the unwanted notification problem.
I hope that helps explain things.