[int_19h]

To repeat, it's not physically possible to judge every single thing. It doesn't matter if you're literate and engaged - there's just not enough time, even if you were to spend every hour you have on this. And most people have jobs etc.

[kobeya]

This is simply not true. Once literate it often takes a minimal amount of effort — back of the envelope calculation or google search— to do a first pass test of the veracity of a source.

[lovich]

You're still relying on another party when you do a Google search, hell if you want to get crazy about it, you are relying that you were correctly taught literacy and that when you read a word, the meaning it has for you is the same meaning the author attributed to that word. It's not guaranteed