Maybe I should read the article.
Silly man, if you want to read articles then you should go elsewhere...
But it implies that all apps can be hacked, which is clearly misleading. Saying "Some Mac App Store Apps Already Hacked" would be more accurate, but much less sensational.
The way you are reading it, it should say "All Mac App Store Apps Already Hacked" but they never said all. The way it is written only implies that Mac apps in the store have been hacked, which is correct.
How do you know they are? Unless you can prove, without a doubt, that you are acting in self-defence because there is actual, imminent and certain life-threatening events, you should not be firing a gun at someone with the intent to kill.
It's easier to prove when the other person isn't alive to discredit your story.
Prof: So the American government went to IBM to come up with a data encryption standard and they came up with ... Student: EBCDIC!"