Liberal Bias in Wikipedia
One clear example is here.
An editor who goes by the handle Gamaliel has decided that the conservative media watchdog organization Newsbusters is not a reliable source. Apparently, the editor deleted material gotten from Newsbusters.
Newsbusters is a conservative source. And their posts are virtually always supported by primary source text or video of the media coverage they consider “biased.”
If Wikipedia excluded all sources with an ideological bias, excluding Newsbusters might make sense, but then the New York Times has an ideological bias.
But in fact, this same editor accepts the liberal media watchdog site Media Matters as a reliable source!
And then another editor insists that liberal activist group FAIR is an “accurate and reliable source.”
Apparently, “reliable” means “agreeing with my ideological biases.”