Pro PHP Security: From Application Security Principles to the Implementation of XSS Defenses, Second Edition

Who Are the Abusers?

If you have not managed a publicly available application or service that is subject to such abuse, you may be wondering just who these problem users are. The full spectrum of abusers can, we believe, be grouped into three categories, based on their motives for acting against the generally accepted norms of online behavior.

Spammers

To date, the most prominent form of identity abuse has come from users trying to market a product or service, or trying to increase their sites' search engine rankings by sowing links on other sites. The activities of a spammer might include the following:

• Posting advertisements
• Posting bogus product reviews or other commercial spin for their own products or against a competitor
• Starting pyramid ...