Sorry if I wasn't super clear on the issue i'm trying to understand it myself. Basically i've seen news lately saying X person Defamed/slandered Y person and as a result they are going to court. Though i've got a clear definition now where it seems that slander/defamation is a person lying in an attempt to discredit someone while free speech only gives a person the right to say "I don't like that person" with that being it.
That's pretty much it. You don't get in trouble with the law, but someone might get pissed off and break your nose

(even if what you're saying is true).
If you say that company Xray is doing something nasty, the government won't do anything to you*, but Xray is within its rights to sue you. Whether or not they'd win would depend on what proof you have (if what you're saying is true, a judge is likely to side with you), and a few other things such as how you spread the information (slander is pretty much just speaking about it, whereas libel is where you publish it... my understanding is that the former is difficult to build a case against). And even if they
do win, it would be a purely civil case and therefore about the worst you would suffer is having to pay a substantial sum to the affected party.
*Except, if you are likely to have broken laws to obtain the information, possibly investigate
that crime. 'Course, if what you have brought to light has enough value to outweigh what you did to get it, the latter may be overlooked.
I have heard USA-style 'free' speech called "protected speech", which does sound a little more accurate -- you're not free to say
anything you want, but you are protected from punishment for most things.
Obviously, this is only my understanding of how things are in the United States of America, should therefore not be taken as legal advice, and is of limited applicability to other countries (in Australia, for example, freedom of expression is only protected by common law/case precedents, and there are things such as http://www.google.com.au/#hl=en&q=sedition&tbs=dfn:1&tbo=u&sa=X&ei=bbDzTr6GEK2BsgLfsbi5AQ&ved=0CCkQkQ4&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=440660d03c957758&biw=1680&bih=859 laws which explicitly limit what one is allowed to say).