Sharing a Map That Half the Audience Cannot Open
A regional agency wants to publish an interactive map of monitoring stations to its public website and to internal staff. The station layer lives in an enterprise geodatabase and includes a confidential contact field and precise coordinates for sensitive sites. The agency has an ArcGIS Online organizational account. A staff member proposes to share the web map publicly so anyone can view it, arguing that 'public maps are read-only, so the confidential field is safe.' The agency also needs internal staff to see the full attribute set.
1. Assess the claim that a public read-only map protects the confidential field, and outline the correct sharing design.
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The claim is false. A public map exposes the underlying data service, and anyone who can access the service can query its fields and often export features - read-only refers to editing, not to confidentiality. Publishing the layer with the contact field and precise sensitive coordinates intact would disclose both. 'Public' is a data-access decision, not a UI decision.
The correct design is to separate public and internal views of the data. Create a public-facing layer that excludes or masks the confidential field and generalizes or withholds precise coordinates for sensitive sites (for example, a symbolized or offset location), and publish that as the public web map. Keep the full-attribute layer restricted to the organization and share the internal web map only with the appropriate groups. Use separate services or layer views so the public map never points at the sensitive source. Verify by opening the public map as an anonymous user and attempting to query the confidential field.
2. How would you verify, before launch, that the public map does not leak the sensitive information?
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Test as the audience, not as the author. Open the public map in a private browser session with no organizational login, then attempt to (1) identify features and inspect the attribute list for the confidential field, (2) query the underlying service directly and request the sensitive fields, and (3) export or download features if the service permits it. Confirm the sensitive coordinates are not recoverable from the public layer's geometry. Also check the item's sharing settings and any dependent services, since sharing a web map can expose layers that were individually shared more broadly than intended. Document the test results. If any step reveals the field or precise coordinates, the map is not ready, regardless of how it looks in the viewer.