QUOTE(sourabhthaver @ Mar 29 2014, 01:09 PM)
Google penalty which always effect lots of websites.
There is a ton of ways to get hurt by google. A few reasons include over optimization of certain keywords for seo, bad links from adult/ pharm websites, if you trigger the unnatural link algorithym by creating a ton of tier 1 links quickly.
What did you believe you did to hurt your rank?