In an email sent to their users this February, newsletter platform Substack apologized for a data breach in their company, which had allowed a third party to access user emails and phone numbers without permission. Substack's site has over 50 million active subscriptions and 5 million paid subscriptions. The data breach allegedly happened five months ago, and Substack clarified that the problem has been solved going forward. Additionally, more sensitive data such as credit card numbers and passwords were not affected by the breach. Other details about the data breach have not been disclosed.