Twenty phone companies may soon have all their voice calls blocked by US carriers because they didn’t submit real plans for preventing robocalls on their networks.

The 20 carriers include a mix of US-based and foreign voice service providers that submitted required “robocall mitigation” plans to the Federal Communications Commission about two years ago. The problem is that some of the carriers’ submissions were blank pages and others were bizarre images or documents that had no relation to robocalls.

The strange submissions, according to FCC enforcement orders issued yesterday, included “a .PNG file depicting an indiscernible object,” a document titled “Windows Printer Test Page,” an image “that depicted the filer’s ‘Taxpayer Profile’ on a Pakistani government website,” and “a letter that stated: ‘Unfortunately, we do not have such a documents.'”