You have probably seen secret documents released by the government on the Internet. More often than not you will see black boxes where some text used to be. This is most likely due to protecting extremely sensitive or secret information from being disclosed to foreign governments.
Unless your business involves training secret agents or provocateurs, you may not feel a need to redact information from documents which you will share. You may wish to think again and review new documents before releasing them for public consumption.
Customers want information on how your product or service has helped other companies improve their business operations. One of the best ways to do this is through customer case studies.
Many of your current customers may be happy to share their experiences, but may not wish detailed locations or addresses of facilities released. They may provide you PDF documents to share, but will request you to redact such information.
Customers may write letters telling you of how you helped them or helped them to reduce expenses and increase productivity. First get their permission to publish their letter then scan it to a PDF document. Redact their address and phone number and maybe even their last name before publishing or using it in advertising.
Many companies have customer letters framed on their walls and customer waiting areas. It is easy to scan such letters, file the original letters and then redact personal information before framing the document and putting it on display.
Redacting text using Infix is real easy: Select the text with the Text tool (circled in red) and then do a Ctrl-Shift-R to redact the text. It is really simple!
Redacted Document via Flickr