User can revoke third-party service access

The updated policy discloses that Substack obtains additional information from third parties and sources beyond what it directly collects from you on the platform. This third-party information is combined with platform data to provide what Substack describes as more relevant and safer experiences, and to improve platform analytics. The policy also clarifies that Substack shares account identifiers with child safety industry consortia and receives information from them to detect CSAM. You can review Substack's full privacy policy to understand which third parties may be sources of this information and how your data may be combined with external sources.

The updated policy discloses that Substack shares account identifiers (email addresses and usernames) with trusted child safety organizations to detect and prevent online child sexual exploitation and abuse. Users now have the right to object to processing of their personal information for personalization purposes on grounds relating to their particular situation, and Substack commits to responding to privacy rights requests within one month. The policy also clarifies that while recipients of direct messages may retain them independently, the platform may restrict your access to messages when other users delete or block you. You can exercise your right to object to personalization processing by contacting privacy@substackinc.com.