Highly entertaining clues as to why you might be wrong, yet quite ... astute. It's quite a good rule of thumb. In fields that I'm not overly familiar with, it quite similar to the rough guide I use internally when trying to come to some provisional opinion. Summarized it goes something like: Who is this everyone who says this? Even if everyone does say that, doesn't necessarily make them right. Take chain emails and facebook warnings with a truckload or two of salt. If it's cutting edge, again with the salt, you're into speculation territory. Scientists/professionals get paid to spend their lives studying shit, there's probably a consensus and that's a good place to start. Technically, they might all be wrong, but it's highly unlikely. And declaring large chunks of science to be wrong, without the backing of some spectacular evidence and a decent chunk of aforementioned professionals - bad place to be.