Using AJAX blocks to hide content from search engines.Browser Info Environment
It also warned that AJAX loaded content would not be indexed by search engines. But maybe you actually want that. Maybe you have content you don't want search engines and robots to see. In this case, you can set the content to be AJAX loaded knowing that any search engine or robot will only see the original page before the AJAX content is rendered.
For example, suppose you want to show a whole directory of user's information, with email addresses, telephone numbers, contact details, street addresses etc. But you don't want that to show up on a search engine or be caught by spammers, call centre auto diallers or junk mailers who use web crawling robots to grab such information from web sites.
There are other ways of encrypting email addresses or any of this information to hide it from all but real visitors. Nevertheless, just loading the whole list using AJAX is an easy way of doing it.
If you want to be really secure, you could even load a block of encrypted information by AJAX.
However, Google attaches greater weight to the top of a page than the bottom of a page.
Loading the top part by AJAX means that Google will see the content lower in the page and index it accordingly.