text: A further difference among these types of hacker lies in their methods of discovering vulnerabilities. The white hat breaks into systems and networks at the request of their employer or with explicit permission for the purpose of determining how secure it is against hackers, whereas the black hat will break into any system or network in order to uncover sensitive information for personal gain. The grey hat generally has the skills and intent of the white hat but may break into any system or network without permission.
  According to one definition of a grey-hat hacker, when they discover a vulnerability, instead of telling the vendor how the exploit works, they may offer to repair it for a small fee. When one gains illegal access to a system or network, they may suggest to the system administrator that one of their friends be hired to fix the problem; however, this practice has been declining due to the increasing willingness of businesses to prosecute. Another definition of grey hat maintains that grey hat hackers only arguably violate the law in an effort to research and improve security: legality being set according to the particular ramifications of any hacks they participate in.
  In the search engine optimization (SEO) community, grey hat hackers are those who manipulate websites' search engine rankings using improper or unethical means but that are not considered search engine spam.