Libel practice

1. “Up until the day he died, he was a brilliant writer. But the drugs made him a thief, a pimp and a liar,” said friend Karen Smith, who was with Johnson at the time of his death.

Not Libel depending on the state.  You can't libel a dead person in most states. The source is trusted, also.  Smith was at Johnson's side upon his death.

2. “Megan Fox is a man!” Headline on Weekly World News Web site

It's satirical (hyperbole), Fox is a public figure, and WWNews is a parody paper.

3. “In my opinion, Kevin is a murdering rapist,” the prosecutor told the jury.

Not Libel.  This a quote from part of the trial. 

4. "In my opinion, he's a murdering rapist," the man said at the rally.

Libel.