Which statement about Person Accounts is NOT true?

The statement that Person Accounts can be modified by any user is not true because access to modify Person Accounts is governed by the same permissions and sharing rules that apply to other records in Salesforce. This means that only users with the appropriate permission sets or profiles can edit Person Accounts. Typically, the ability to modify records is restricted based on the user's role, profile settings, and the sharing model implemented in the organization.

In contrast, the other statements about Person Accounts are accurate. They are indeed displayed as a single record, effectively combining elements of both person and business account types. Additionally, enabling Person Accounts requires action from Salesforce Support, and once they are enabled in an organization, they cannot be disabled due to the architectural decisions made within the Salesforce platform. This ensures consistency in data management and system functionality.