If you like to prevent Google from crawling certain information available in text format, try HideText. This service converts text into a human-readable image that won’t be indexed** by search bots plus it may be used as an alternative to prevent copy-paste on your website.
You may download the converted image locally or just hotlink to the HideText server where that images is hosted forever. The technique can also be used to prevent AdSense PSAs.
Here’s a sample scenario where HideText says their service could be of use: you want to ask a question in some public web forum but won’t like the whole world to know about your problems are. Since Google will certainly index that forum thread in future, you may certainly hide the question text from Google by using an image instead of text.
**Google can read text inside scanned PDFs but they’re yet to extend their OCR technology into images.
This is converted to an image which is hosted by HideText, that can now be used at places like a blog, website or forum. Thanks MakeUseOf.