Currently, all blobs stored in Walrus are public and discoverable by anyone. This means you shouldn't upload any sensitive or private data directly without securing it first. You need to handle the access control of your content on your side before uploading it to Walrus. To secure your data, you can use the 'Seal' service for encryption and on-chain access control. Seal allows you to encrypt data ensuring that no single party holds the full decryption key, and define access policies that determine who can decrypt the content and under what conditions. By integrating encryption through Seal, you can store encrypted content on Walrus, which keeps decryption logic verifiable and flexible. This setup is particularly useful for sensitive documents, game assets, private messages, and any data you need to keep confidential.