Of course they aren't putting it on ChatGPT. Their data is stored in S3, Snowflake, BigQuery, or Azure Storage. It makes more sense to use the respective cloud provider LLM hosting service. You can use OpenAI's GPT models or Anthopic models hosted on Azure or AWS.

You're telling me companies in Europe aren't putting all their user data on AWS and Azure regions in Europe? Both AWS and Azure are gigantic in Europe.