While online communities have existed since the inception of the web, their importance and potential are finally being recognized and explored with Web 2.0 services such as blogs, wikis, online writing sites (HubPages, Squidoo), social networking spaces (Facebook, mySpace), social bookmarking sites, and much more. This new era of online communities has brought great possibilities, but as with any big change, there is also the potential for abuse.

Community hacking is the art of breaking into online communities, and bending their function in unintended ways. While certain forms of community hacking may actually improve user experience, most are geared towards personal gain and will ultimately hurt quality of content and online community interactions.

The primary reason for hacking into an online community is to hijack web traffic. With services such as Google Adsense, it is extremely easy for users to place advertisements in their websites or webpages and translate web traffic into revenue. To get enough web traffic for any kind of revenue effect, though, requires a fair amount of self-promotion.

The fastest way to self-promote is through community hacking.

1. Spam links on social bookmarking sites.

To drive traffic quickly to their personal websites, community hackers will join a variety of social bookmarking sites (Digg, StumbleUpon, del.icio.us, reddit) and add links for each and every one of their webpages. They may then ask friends to help vote up their links. Alternatively, some use programs to automatically ping their links so as to imitate web traffic.

This type of community hacking not only falsely elevates non-relevant links, but it also inundates the social bookmarking sites with a large amount of spam traffic.

Signal to noise ratio decreases, transactions slow to a crawl, forums get jammed with complaints, and ultimately the community fails.

Because of the serious ramifications of community hacking, community managers often take strong measures to curb this behavior. For example, many social bookmarking sites such as reddit and del.icio.us automatically ban content from well-known community hacker domains such as HubPages.com.

In fact, only a relatively small number of HubPages participants engage in community hacking, but unfortunately, their tenacious efforts have caused the banning of the entire domain.

Other social bookmarking sites, such as StumbleUpon, have stringent rules such as limiting the number of links you can submit from a particular web domain. Over promotion across multiple bookmarking sites will also get you dereferenced from Google and possibly other search engines.

2. Mirror content on multiple blogs and social networking spaces.

The fastest way to get as increase web traffic is to create many webpages that people want to visit. However, creating high quality content is a long and laborious process; which will cut into the bottom line.

The community hacker's solution? Copy and paste.

Steal good content, integrate it, and duplicate it across a variety of blogs, and webpages. By creating mirror sites, we cast our content to a wider audience, and increase our probability of getting clicks. Mirror sites also allow us to subvert the domain link limit rule from social bookmarking sites.

This type of community hacking is much harder to stop as it targets the internet as a whole rather than any one particular service. Since the hacking occurs across multiple applications, it is difficult for any one application to get the gestalt view without sharing user data, which has its own issues.

The people who are best able to capture and stop this type of community hacking are the search engines. Search engines also operate on the internet as a whole, and since their bread and butter is in analyzing text, they are well equipped to detect mirror sites and duplicate content.

However, duplicate content will likely cause all offending pages to get dereferenced. This may inadvertently penalize the original creator whose content was plagiarized, and is now banned.

3. Thread hijacks and spam posts on message boards.

Community hackers may hijack a popular message board thread by making a post that is totally unrelated, but which contains links to their webpages.

This practice quickly degrades the community experience because users must sift through promotional ads while trying to get to the relevant content. Because of these actions, many message boards now frown upon link postings. While such limitations may stop this type of community hacking, it also prevents valid links from being posted.

Perhaps a more friendly way to self-promote links is to join message boards that are based on topics which you know a lot about. In the process of answering questions, you will have many opportunities to self-promote relevant content. I do not see anything wrong with this type of community hacking, as the user is also providing a useful service to the community.

It is clear that online communities are starting to take community hacking more seriously and are fighting back. By implementing additional rules and limitations on user actions, they may have stopped the initial wave of community hacking. However, once a hack is stopped, something new will probably crop up. As with the system hackers of old, this will be a back and forth fight.

Community hacking will never be stamped out because the rewards are great for those who succeed.

In the meantime, the online community experience will deteriorate because more and more rules will have to be mandated to stop the next wave of community hacking. Unfortunately, some of these rules will also hinder legitimate users from useful community building actions.

One of the strongest weapons against community hacking is to rely on the community itself. Members can flag administrators when they spot hacker type behavior. Ironically, the better community hackers will get high visibility for their webpage, and it is exactly this success that brings them under the eye of the community and ultimately gets them flagged and banned.

Perhaps the solution to community hacking lies in finding better ways for related communities to share services and establishing a protocol for interaction among their members.

By providing users with a legitimate path to success, there will be less need to hack the community.