Most HEIC converters start the same way: "Upload your photos to continue." It feels harmless — until you think about what you're handing over. HEIC is the default photo format on iPhones, so the pictures people convert most often are exactly the sensitive ones: family photos, IDs, receipts, medical documents, screenshots of boarding passes. When you upload a file to a converter server, three things happen that most people never consider. First, you lose control of retention. Many services kee...