Bots aside, what we post on the internet (and believe in general) is a function of the information we consume. That information is increasingly consumed through the internet, and the internet (as typically used) is feeding us increasingly poor quality information. (To be consumed, then shared. Recurse...)
We can (and I think do) cope by having different levels of trust for different sorts of internet information. I generally have higher trust in an HN post than an Amazon review, for example. This is useful, but has a dark side: some of the things I (and likely, you) take as a sign to "increase trust" happen to correlate with things that have nothing to do with trust. I trust Amazon reviews more if they have good grammar and spelling, largely because I trust general internet information more when it has good grammar and spelling. But perhaps I shouldn't when e.g. buying a screwdriver (what does writing ability -- and the things it correlates with -- have to do with evaluating a screwdriver?). Coming up with social/political-flavored-information examples is an interesting (and worrying) exercise.