SEO is the development of search engine synchronization. In this development process, search engine and SEO to a certain extent form a kind of competition relation.
On the one hand, search engines in the process of searching the site, feel the convenience of SEO to them, so that the site after optimization can be easily crawled by them, improve the search accuracy and information. On the other hand, SEO practitioners always want to spy on the search engine ranking rules, so that their site can easily be optimized according to these rules, trying to occupy an advantage in the search results position.
At the same time, Seoer found that the search engine loopholes and defects, will not be how the site or spam sites submitted to search engines, shoddy, cheat search engine rankings. This will inevitably be a reasonable site optimization technology pollution, so that the search engine actively modify their own algorithm, to counter these SEO attacks, this shoddy, rely on fraud to carry out the practice of SEO activities in the English-speaking world is called Black Hat practice. Contrary to Black hat nature is a white hat.
As for what is acceptable behavior, what is not, this is determined by the search engine itself, opponents said: Black Hat practice is to rank and ranking approach, not help site users to provide a useful site ranking method. Indeed, I agree with that, however, how to define what behavior is illegal and search engines are judges. The different search engine has given us stationmaster certain station guidance, but many is more vague, this is because the search engine does not want to reveal a trace of their own algorithm. In order to avoid the black hat to reverse reasoning, design more crack methods. For example, Yahoo prohibits any "to bring users a bad experience of the Web page" This sentence is very general, bad use of the experience of the Web page, what is, we do not know, to rely on our own to guess, to explore their own.
Regardless of the definition of Black hat and white hat is justified, but if you use some extreme manipulation and eye-impaired, playing tricks on search engines, your site will be excluded from the search engine. You should not be surprised at the result. We are doing optimization, or seriously do it, we do the station is for users to see, rather than search engines, ranking is just a means.