Can search engines ban websites???

any black hat techniques used and you wll be banned

 

if your manipulating your PR... doing black hat techniques.... it will cause your website banned...
just follow SE rule... and be good White Hat

 

yes but very rare situations

 

the main reason for this is by practicing a black and gray hat by those got banned their sites by search engines. And here are the examples of on page spamming which are image alt tags spamming, meta tags spamming, title tag spamming and of course the hidden text!

 

Yup, Search engine can ban your site specially when you got caught by search engine selling, buying link or sometimes using unethical technique like black hat.

 

Yes every search engine have theier own policies and if some website violates it it get banned from that search engine. Only a few days ago text-link-ads was banned from google.