What can cause you banned from Google

[boron]

Spam. Stuffing your site with keywords and unsolicited mails through your domain mail go here.

Link Farming. Site with no real content, only links.

Cloaking and Doorway Pages. If you made one page and SEO it for Google then you made anothrer one for public and redirect first to second - this is one example of cloaking.

Selling PageRank - selling backlinks from your website. (Personally I've never heard that this really happened to someone).

Excessive Cross-Linking Creating a lot of websites and cros linking among them.

I found this on one site where some other reasons for banning were mentioned, but I doubt in them, so will not even show a link.

[Mystic]

And other blackhat techniques (http://www.google.com/search?client=opera&rls=en&q=blackhat+seo&sourceid=opera&ie=utf-8&oe=utf-8).
Dont do stupid things like using same colour background and text to hide links, putting irrelevant meta tags etc.

[Chris369]

I didn't think cross linking was bad. If it is, how come Weblogs Inc (engadget, ps3fanboy, xbox360fanboy etc) aren't banned from Google? They have loads of inter-linkings.

[Mystic]

Yes. Google doesnt actively discourage link exchange (AFAIK). Only, that both sided links have a lesser value.

[Submerge]

Thanks for the list man, need to definitely stay away from those practices. I've never had a site banned by Google's search engine, so if you do it probably is your own fault.

[boron]

I didn't think cross linking was bad.

It applies only for "excessive" which is not the same as "a lot". If you have a lot of sites on the same IP, Google will find out that are from the same person. If their content is almost the same, they will be considered as spam and will not get weight in Google SERPs.