To clarify, you can say whatever you want as long it is a) truthful and b) you have evidence that supports that truth. No, you can't start a blog or write posts on how certain people are pedophiles because you don't like them without any hard evidence of the accusation. No, you can't accuse a business of a crime because they provided you poor service and you want to get back at them. Both of those will end up in trouble, probably for something like slander or reputation damages. However, you can write about why you don't like a particular person, or document the incident of poor service. Since both of those are more opinion-based, you don't necessarily need evidence to prove it. Here are a few more of the many reasons why bloggers can't say whatever they want, whenever they want, on their blogs.
Freedom of Speech Isn't Absolute
The First Amendment does prohibits the making of any law "abridging the freedom of speech" or "infringing on the freedom of the press." However, the Supreme Court has recognized several instances where governments may enact reasonable time, place, or manner restrictions on speech, such as the protection from imminent or potential violence against particular persons, or the use of untruths to harm others. These restrictions include bloggers, who must exercise this oversight themselves, whether they considered themselves individuals or members of the press. The press exercises this oversight as well, ensuring that what they print is accurate and doesn't lead to a case of slander or reputation damages.
As Lorelle VanFossen so brilliantly puts it in the Blog Herald, "Sure, you can say whatever you want, but there are consequences you must live with if others don’t like what you say, or the law disagrees with your right to say it."
You Can Be Held Responsible if You Republish Libelous Content
Libel and slander are slightly different things. Libel is strictly the publishing of a false statement that harms the victims reputation, while slander is the publishing of a false statement with the intent to harm and with knowledge of it being false. However, even if you were to republish a libelous statement (and were not the original writer), you could still be held responsible for libel, even if you thought the statement was true or you didn't intend harm with the statement. There are two good ways to avoid libel claims: tell the truth, and/or clearly distinguish fact from opinion. In blogging, the individual blogger is responsible to the law in the same way as traditional press, even though factors like the speed of publishing, the lack of editors, and the prominence of cutting and pasting make blogging much riskier in media law than other types of outlets.
Invasion of Privacy is Also Important
Say that as a blogger you know something to be true, that someone is committing a crime, and that you do have evidence to prove it. However, if that evidence was obtained through an unlawful invasion of privacy, then you could still be held liable for defamatory comments. Examples of unlawful invasion of privacy include breaking into a home, office, or e-mail to retrieve information or the use of impersonation to retrieve information.
A non-public individual has a right to privacy from: 1) intrusion on one's solitude or into one's private affairs; 2) public disclosure of embarrassing private information; 3) publicity which puts him/her in a false light to the public; 4) appropriation of one's name or picture for personal or commercial advantage. It should be noted that this only applies to non-public people i.e. those who have not voluntarily put themselves in the public eye. Those who have voluntarily put themselves in the public eye are considered newsworthy, even their personal and intimate lives. A politician would count as a public figure, while a CEO of a small company wouldn't be a public figure.