Let’s say I have an ASP.NET web application. I create an aspx page that shows a table containing users and email addresses. The user data is stored in a database, and when the page is requested by a logged-in user, html is generated to display the data. If the users requesting the page are not logged in, they are redirected to a sign-in page.
All of this is very standard.
My question is, is there any way the personal data could end up being indexed by a search engine (besides someone hacking into the site or an evil user publishing the data somewhere public)?
What if there was no requirement that users log in? Would the data then be indexed?
In general, search engines should index exactly whats visible to the public visitors, google will be angry with you if you’ll expose something different to their spiders.
if you want to control the pages that are indexed on you server check out: http://www.robotstxt.org