Purge
The "purge" was part of the Spring Cleaning and occured on April 23rd, 2005. All JAKs and JATs of the Jedi Academy were placed back into the rank of student for re-evaluation, mainly due to inactivity within the ranks. Some of the original JAKs and JATs were reinstated but it took the Jedi Academy months to get a sufficient staff.
All was not well within the Academy
Those who hold a rank as JAK+ are required to meet a number of standards. Massadoobie clearly mentioned Gaming skill, Activity and Attitude in his State of the Academy newspost on April 17th, 2005. Gaming skill is important, because a JAK+ is required to be a balanced player as well as having at least one area of expertise. Activity is also a standard for two reasons. The first reason is that JAK+ can only do their job if they are active. However, activity also affects skills, as a player must regularly train ingame to secure his or her skillevel. The final and most important standard is Attitude. JAK+ must be friendly, helpful, respectful and follow the rules. If they meet all of these requirements, they can serve as rolemodels to other members of the Jedi Academy.
However, there were some issues going on. Many of the JAK+ members had slowly but steadily become less active over time to the point that some were inactive completely. This has affected not only their activity, but caused a decline in skillevel as well. The result was that some JAK+ weren't around as much as they were required to and when they came online, they got destroyed by students. Intervention was necessary and the Jedi Academy Council responded accordingly.
Measures
As of April 23rd, 2005 all Knights, Trainers and Staffmembers got their accounts reset to the level of Student, which became known as the purge. All classes were cancelled with the exception of Virtue's. New trials had been created that were a lot harder than the original ones. The idea behind this was that it allowed for a more thorough scrutinization of any trialee.
Replenishing the ranks
Once the measures had been in effect it was time to refill the ranks. Not all former JAK+ suffered from the issues mentioned earlier and they were toggled to face the new trials. Some students who hadn't been in the JAK+ before were also toggled. Virtue trialled Luke Skywalker, Jaiko D'Kana, Jaina D'Kana and Gradius who were former JAK+. Upon completing their trials they were each given the rank of Jedi Academy Master.
Additional JAK+ poured in over time, albeit slowly. The reason for this was the fact that trials were conducted by JAK+ and there were very few of them present due to the purge. As a result, it took a good number of months until the Jedi Academy managed to get back to strength.