Years and years ago, The Girl and some others were arguing with McGentrix. So he went off to Wikipedia, signed up, and then edited an article to support his claim--which the article had previously refuted. The Girl contacted Wikipedia, and the article was fixed. McGentrix got banned from there, or rather, whatever name and e-mail he had given was banned. Really, i suppose the only surprise should be that this has not happened on a large scale much sooner.
With the christian vandals, they were rather stupid to begin with. In the article on the historicity of Jesus, they claimed that Trajan's letter to Pliny was evidence for Jesus. That was stupid and clumsy. One might try to argue that Pliny's letter to the emperor is such evidence, although that would be a stretch. But there is no way Trajan's letter could be such evidence--he doesn't even mention christians. That must have been an embarrassment to them. There was a whole pile of specious crap in that article, too. The editorial staff just completely restored the previous text.
Eventually, though, the nickel dropped, and now they just go in an make insertions, and then battle with the ones who dispute their claims on the talk page. That works much better, because their changes stay until the dispute is resolved, and if it is not resolved,, then the changes stand. Then they whine about staff editors who put the "citation needed" tag in the text. Their methods are insidious, and as they perfect them, they are effective. I think others are taking a page from their play book, too.
I just deleted a long description of another gross error in a Wikipedia article which i find has now been fixed. But then, the Hundred Years War is not a rligiously or politically controversial subject, and those who do care about military history care passionately about accuracy, which is, i suspect, whey the article was corrected just ten days ago. When the subject is religion or political ideology, or even just influenced by then, i think the odds of corrections being made and maintained
, is very low.