Okay, don't use it then. They make no claims of enhanced privacy and frankly it's unreasonable to presume a service such as this would do all processing locally unless you're paying a premium for that ability. Or did I miss the "Great for confidential documents!" banner? For most peoples' use-cases, this is not a concern.

If you need a private OCR server that you can host yourself (locally or on the cloud), shoot me an email.