Site de-indexed - Quick Text View>
- Has there been any removal requests via webmaster tools?
- Has your site been hacked or compromised recently or currently?
- Do you have a message from Webmaster Tools mentioning hacked spammy content ?
- Do you show different content to googlebot and users with the intent that users should not see the text?
- Have you very recently purchased the domain and it is preowned?
- Do you have a DMCA notice and/or is there one in the search results when looking for your site?
- Do you have any other sites that are in any way similar?
- Do you duplicate, copy, or rewrite content that can be found elsewhere?
- Is your site themed around an affiliate scheme?
- Does your site contain a very large amount of non-exclusive content?
- Have you recently amended or removed problem content?
Update April 2012 : This information is still current. If you have been given another reason not on this list for your site to have been de-indexed then treat with caution and look for authoritative supporting evidence.