"no way for readers to tell"

There is a good article on The Washington Post's website about how the New York Times ran three big stories that all relied mainly on unnamed sources. It's a good example of how online independent news sites can seem more credible than traditional media outlet, allowing the reader to investigate the journalist's claims and judge for themselves. If these stories ran on a blog it is likely that most readers would doubt their credibility, and the sources motives, straight away.