Re: What's the constitution got to do with anything?
As I understand it, if you can prove the truth of your statements, it's not libel. Even if it harms someone's reputation. The problem is where you can't. In England and Wales (Scotland has a different legal system) you can allege something you believe to be true, but if you can't prove it to the jury's satisfaction - then you lose. And the burden of proof is on you, the defendant, which is unusual compared with most other types of case. So Private Eye lost to Robert Maxwell about his theft of company money, because they had the right inside info, but were unable to prove it. And even after his death, and wrongdoing became public knowledge, I seem to remember they tried to recover their libel loss from his estate and still didn't get it.
The US is different. It's not truth that the Constitution protects, it's freedom of speech. And I think the US leans far more towards fair comment. If you weren't publishing it maliciously and you sincerely believed it to be true, and had actually done some checking, then you don't have to prove your allegations to the civil court standard of "in the balance of probabilities". Criminal standard being "beyond reasonable doubt", of course.
Biting the hand that feeds IT
