The Facebook activity of users aged between 13 and 17 would have limited visibility in the network's new "social graph" search facility, the firm said.
The first was for Graph Search, an advanced search tool for more effectively drilling down into your Facebook to network to find people and pages and companies.
And unlike an open social network, where everyone is equal, NationalField runs on a hierarchical social graph: Higher-level staff get a broader view of the state and local work below them.