The internet allows us, for the first time, to have many-to-many communication. It also allows us more information than we've ever had before at our fingertips. This has led to the ability to provide feedback on news articles and for informed discussion over a range of topics. If an argument is presented, you can quickly look-up any background information or confirm certain facts to present a well formed argument in response.
This is highlighted no better than in game forums, where such is the level of familiarity of the subject matter, that the complexities involved in the medium can be boiled down into a single phrase along the lines of:
xbox sux ftw
halo rox - woot
... regardless of the subject being discussed. I'll be dealing with common misinformed (or generally assumed) forum statements from the ignorant masses; opinionating on things they actually know nothing about.
It would seem that as long as you don't actually play or spend any time finding out the details of what you are talking about, you can rest easy behind your shield of ignorance. In the land of forums, not knowing you are wrong seems to be considered to be the same as being right.