As to that, I agree in general, but would counter that it completely depends what you read. Photoessays from journalists on the scene in Syria are news. Articles on the state of the bitcoin from experts are news. Hard not to benefit from knowledge if you know what you're doing.
I follow US politics for many reasons, not least of which is that it makes election night very interesting when it otherwise would be confusing and pointless. But I would say that yes, having a general knowledge of politics does tell you what's going to be a lie in some cases -- various politicians have been promising to hit a budget surplus consistently for years now, and none of them have done it for very long ... now Paul Ryan wants to. Should I believe him? Nope.
World news indeed will not tell me how not to get mugged in my own town. (I'm honestly not sure why I should expect it to?) Common sense will probably help me out there, though.
The best financial forecasting in the world isn't really 50/50, either. There are plenty of ways to safely invest money longterm for a guaranteed small return -- but only not having your head in the sand and knowing a bit about economics would have told you not to invest in real estate in 2007.
I believe this to be the fundamental reason why reading the news is sometimes bad for you: it can lead to a false sense of certainty about the world and then distress when that illusion is shattered.
This is utterly and completely a personal problem (not your personal problem; a common problem that people have when attempting to separate fact and opinion). Bad proofs can lead to a false sense of certainty about math, but we don't swear off math as a result, usually.