This is a monumental decision by the Arbitration Committee. Individual people have been banned before from editing on Wikipedia pages, but never before has such a large organization been banned completely from editing Wikipedia pages. The case has been running for a while now, but the evidence presented was convincing enough: members of the organization that calls itself a church, but many consider to be a dangerous cult, have systematically edited relevant pages on Wikipedia in an organized fashion. The banning is achieved by blacklisting all IP addresses owned by the Church of Scientology. The ban covers all of Wikipedia (not just Scientology-related articles), and is effective immediately.
A former member, Tory Christman, has detailed to El Reg that the organization has a sort of PR division which actively looks for criticism on the web, with the goal to remove it. Wikipedia is of course a sitting duck in this regard, as anyone can edit whatever they want. "The guys I worked with posted every day all day," Christman tells El Reg, "It was like a machine. I worked with someone who used five separate computers, five separate anonymous identities [...] to refute any facts from the internet about the Church of Scientology." Christman left in 2000, before Wikipedia came to life.
To balance the story, it is important to note that several anti-Scientology editors have already been banned from editing on Wikipedia over the past several years; part of a protracted information war between Scientology supporters and detractors.
This is not the first time that Scientology has come under scrutiny. The Belgian government launched a massive criminal case in 2007, accusing the local Belgian branch, the European branch, and 14 members of fraud, extortion, fraud, illegitimate practice of medicine, violations of privacy, and partaking in a criminal organization (applies only to the 14 members, not Scientology as an organization). Eight years of investigating preceded this case, making it the largest fraud dossier ever made against Scientology.
Its status as a religion is also disputed. The German government considers Scientology as a commercial organization, and is pondering a ban, stating it is incompatible with the German Constitution. Greece banned Scientology in 1997, reiterating the ban in 2003. Several other countries have refused to recognize Scientology as a religion, but a few others do recognize it as such: the US, Australia, Portugal, Spain, Slovenia, Sweden, Croatia, Hungary, and Kyrgyzstan. I had to dig pretty deep to find the status of Scientology in The Netherlands, but it appears my government treats it as a "religious movement".
This story shows that while Wikipedia is a great resource to us all, and a testament to what we can achieve as a collective, its openness and freedom is also its weakness, as people with malicious intent can abuse Wikipedia to spread their own ideas, and stifle criticism, whether it's valid or not, and this abuse is even more damaging when it's done in a systematic fashion by an organization with vast labor resources.
It remains to be seen if the massive IP ban will actually stop individual members of Scientology from abusing Wikipedia as the information war continues. It's not difficult to cheat your way around IP bans, so it most likely will be a temporary nuisance and symbolic measure, not an actual solution to the problem.