Google banning is a big deal. It means death to some online businesses. Imagine, if Google won't spider your site, how are you to compete with your online rivals?
To know whether or not you are banned by Google, visit Google's homepage and type in the search box your website's URL (www.yourdomain.com). If your domain is banned, Google will say – "Sorry, no information is available for the URL www.yourdomain.com." This information is shown without any direct link to your domain. If your domain is indexed, Google will show direct links to your domain.
Google banning is a contagious online disease. As a fact, all sites that are link to a banned site are at risk of getting Google banned. Manifestations of the online disease include rapid and severe drop in web visitors and sudden drop of search engine ranking in Google. This drop from any level to 0 includes all the pages of the website. The combination of the mentioned manifestations is highly suspicious.
To prevent the disease from scattering and damaging improved web page rankings, you follow palliative treatment. Treat the cause of the problem, isolate your site from banned sites, and email Google at firstname.lastname@example.org. Further, attach a reinclusion request.