pdf417 barcodes are commonly used on US driver's licenses, and contain private information like the person's address, height, eye color, full name, etc. For the API to do its work in detecting a valid barcode, it needs to be able to read the entire barcode to compute a checksum/checkdigit. Which means it has to read the data.
But this API doesn't allow access to the camera. The caller is responsible for passing in an image to be parsed. Saying it needs to be blocked for that reason is like saying parseInt() should be blocked.
