The following is from a guide about how to identify subversion agents:
Technique #6 - 'GAINING FULL CONTROL'
It is important to also be harvesting and continually maneuvering for a forum moderator position. Once this position is obtained, the forum can then be effectively and quietly controlled by deleting unfavourable postings - and one can eventually steer the forum into complete failure and lack of interest by the general public. This is the 'ultimate victory' as the forum is no longer participated with by the general public and no longer useful in maintaining their freedoms. Depending on the level of control you can obtain, you can deliberately steer a forum into defeat by censoring postings, deleting memberships, flooding, and or accidentally taking the forum offline. By this method the forum can be quickly killed. However it is not always in the interest to kill a forum as it can be converted into a 'honey pot' gathering center to collect and misdirect newcomers and from this point be completely used for your control for your agenda purposes.
Read about more tricks used to derail truth here.