A big problem is also that Wikipedia doesnt get rid of contributors pushing a bias and sabotaging wikipedia pages. Jörg Matthias Claudius Grünewald "Feliks" is just a rather prominent example in the German Wikipedia.
Could you elaborate?
He's apparently an editor who used to be anonymous, converted to judaism and is said to behave manipulatively. But as I said, can't really find reliable information.
https://web.archive.org/web/20180908111231/https://www.nachd...
edit: To give an example, he deleted any mention on human rights violations in Facility 1391 with the argument, that Israel investigated the reports and found no evidence of any wrongdoing. Thats still where the page is today, different to the english version. For other individuals, like Nirit Sommerfeld he altered their Wikipedia page to push them into antisemetic corners.