"Quote"

I've noticed the increasing prevalence of using the "quotation marks" in the media lately... like this past year or so. Very odd. I'm not sure what the rules are for using quotation marks, but I'd like to find out. For example, currently, on CNN headlines:

• Did Hamas use 'human shields'?
  
• Musharraf: U.S. treats Pakistan 'unequally'
• Two children killed by man with 'painted' face
• Freed Gitmo detainee 'went to al Qaeda'
• Tsvangirai: Zimbabwe cholera crisis 'man-made'

Or on BBC headlines:

• Mexican 'dissolved 300 bodies'
• Two detained over Travolta 'scam'
• Court fees plan 'tax on debtors'
• Ledger had 'most fun' as Joker
• Afghan raid 'kills 15 militants'

For the ones where someone is quoted, such as Former Pakistani president cry baby Musharraf's claim, sure, quote the exact word to reflect what he meant. Or the one on Zimbabwe. Those seem like genuine quotes.

But how does "human shields" and "scam" deserve quotation marks? "Most fun"? "Kills 15 militants"? "Painted"? Why not put "painted faces" in quotes? Why just "painted"?

In the Travolta story, the word "scam" doesn't even appear in the article! And in CNN, they reported Two held in Travolta extortion plot. Someone needs to put a stop to this "" non sense. Use them when your news piece cannot accurately articulate the meaning of your report. Otherwise, please don't use quotation marks to "draw attention" to a particular word that "may or may not" have any weight in the story.