Here are just a couple:
To be fair, newspaper journalists have far too little time to do far too much, particularly with the steadily collapse of print circulations. If a story breaks just before the deadline, they may just copy it: but it seems only fair to require labelling in a case like this.
...and we all know what happens when you do this.
Now this'd be fine, if journalists were willing or able to call upon expert sources to verify claims, and then to quote their responses. Otherwise you get front-page headlines about cures for cancer based on small irrelevant studies on mice.