This website is hosted by Squarespace, which has this to say about privacy and security.
Security is one of the biggest considerations in everything we do. If you have any questions, or encounter any issues, please contact us at firstname.lastname@example.org.
Stripe has been audited by a PCI-certified auditor, and is certified to PCI Service Provider Level 1. This is the most stringent level of certification available.
SSL and HSTS
Stripe forces HTTPS for all services, including our public website. We regularly audit the details of our implementation: the certificates we serve, the certificate authorities we use, and the ciphers we support. We use HSTS to ensure browsers interact with Stripe only over HTTPS. Stripe is also on the HSTS preloaded lists for both Chrome and Firefox. For more about implementing SSL on your own website, read our SSL guide.
All card numbers are encrypted on disk with AES-256. Decryption keys are stored on separate machines. None of Stripe's internal servers and daemons are able to obtain plaintext card numbers; instead, they can just request that cards be sent to a service provider on a static whitelist. Stripe's infrastructure for storing, decrypting, and transmitting card numbers runs in separate hosting infrastructure, and doesn't share any credentials with Stripe's primary services (API, website, etc.).