When New South Wales Medical Council staff uploaded a PDF with private information, they simply placed an opaque block over private information. As they later discovered, this isn't enough.
The information wasn't visible to the naked eye, but the data remained -- and was searchable by Google.
While this isn't a desirable thing to happen anybody, in this case it was a Doctor who had her details revealed. And the document was in regards to a decision on a case put before the Medical tribunal. At the conclusion of which it was agreed on to withhold her identity from publication.
NSW Civil and Administrative Tribunal senior member Naida Isenberg stated regarding the case:
"The method used to 'redact' the Applicant’s name merely placed an opaque 'block' over the top of the 'redacted' words. While this prevented the human eye from reading the Applicant’s name, it allowed, as was later discovered, Google webcrawlers (also called 'Googlebots') to read this information and to link the publication to a search of '[Doctor's Name]' (and similar).
"The fact that a Google search of the Applicant’s name resulted in a link to the decision meant it could readily be inferred that the decision related to her."
The council weren't aware that Google’s indexing software had found the name from the PDF's metadata until it was contacted by the Doctor's lawyers, five months after it was published. The name of her son was also revealed in the documents.
But it's not as easy as it sounds to remove something from the internet. It took six months, in the end.
The council reportedly “needed to be told on several occasions that the publication continued to be available via a Google search of the applicant’s name before it was successfully removed.
“Unsurprisingly, on 20 July 2011, Google Australia informed the Respondent that it would take no action."
Searching for the Doctor's name still brings up the Medical Council's website, but not the specific documents -- which means there is no longer a breach of NSW privacy law.
TL;DR Version: Don't just block out names -- it's all still searchable.