The most effective form of lying is lying by omission. It's harder to detect, easier to defend as just ignorance, and is perhaps more effective than outright false claims.
Far far more effective is lying by implication. This happens almost all the time. The article is written in such a way as to imply something is true; for example talking in such a way that said thing is obviously true and everyone knows it, when in fact it isn't true at all. This allows them to make the reader think something is true without lying, and often without even having the reader question it, and it allows the media to not even have to try to supply evidence at all.
Why don't we make a law around it? I'm tired of politicians weaseling themselves out of difficult situations by saying "oh, I forgot about that". It's your job to bring important, relevant information to the table, damn it.
A law to do what, exactly? Criminalize the omission of facts from a statement? Criminalize ignorance?
Who decides when a fact was omitted? Was the fact pertinent (note: there's a lot of wiggle room here)? How much investigation has to be done to uncover whether there was a lie by omission or actual ignorance?
What would the penalty be?
Thinking you can legislate your way out of this is hopeless idealism.
It is physically impossible for anyone to express all facts in finite time. Every expression is, at best, a selection among the facts of that which is adjudged relevant. Legislating what would be relevant in every situation is likewise impossible.
Demonstrating that a fact is omitted with dishonest intent is tricky business. That doesn't mean we can't guess, but the law does not go by guesses.