Here’s the setup: You’ve carefully crafted a web map and application in ArcGIS Online. The data is perfect, the configurations are solid, and you’re ready to share it with your team. But then, you notice something alarming — edits are possible when they shouldn’t be. Despite your best efforts to lock things down, the data is still editable in ways you may not want. This was the exact situation we faced recently. Here’s how we untangled the mystery and discovered (via tech support) a hidden pitfall in group permissions that every ArcGIS Online user should know about.