Charted does not store the data it visualizes. Each time Charted loads, it only re-fetches the data from the link provided. The only user-provided data that we store is the link used to re-fetch the data. Thus, the publicly-hosted Charted.co can only fetch data and provide shareable links for data files that are already publicly accessible to anyone with the link.
We believe Charted.co has sufficient privacy protections for most purposes, but for especially sensitive data we recommend serving your own instance of the open-sourced Charted.