Points to Ponder
The major points of criticism of Wikipedia, an online encyclopedia, are the claims that the principle of being open for editing by everyone makes Wikipedia unauthoritative and unreliable (see Reliability of Wikipedia), that it exhibits systemic bias, and that its group dynamics hinder its goals. Among many examples, the Seigenthaler and Essjay incidents caused criticism of Wikipedia's reliability and usefulness as a reference.
Content disputes are not vandalism. Wikipedia defines vandalism very carefully to exclude good-faith contributions. Accusing other editors of vandalism is uncivil unless there is genuine vandalism, that is, a deliberate attempt to degrade the encyclopedia, not a simple difference of opinion. There are numerous dispute resolution processes and there is no deadline to meet; the wheels of Wikijustice may grind exceedingly slowly, but they do so surely.
Warning others to assume good faith is something which should be done with great care, if at all – to accuse them of failing to do so may be regarded as uncivil, and if you are perceived as failing to assume good faith yourself, then it could be seen as being a dick. There is nothing wrong with questioning the reliability of sources, to a point. But there is a limit to how far one may reasonably go in an effort to discredit the validity of what most other contributors consider to be reliable sources, especially when multiple sources are being questioned in this manner. This may take the form of arguing about the number or validity of the sources cited by the sources. The danger here is in judging the reliability of sources by how well they support the desired viewpoint.