So a blogger gets a tip from a source, knows the people involved, acts on it and smells a rat. He sticks around and talks to a few people he knows, makes a few calls and gets a breaking story. Sounds to me like bloggers are the new journalists and that traditional media is in big big trouble.
a breaking story would name names...him not naming names just means he can use this as a hammer to get better terms for Techcrunch(either I get exclusive to every deal you guys do...or your names will be posted)
Arrington did the right thing. It's not about whether he caught a criminal, it's about whether he prevented someone from becoming one.