Yup, but there could be reasonable suspicion for a warrant...
The real questions in my mind are:
1. Whether bloggers count as a protected class (journalists). I don't think bloggers are explicitly listed under the law.
2. Whether the receipt of a prototype phone, stolen or not, would be protected under the Privacy Protection Act.
On one hand, if Chen is being investigated then it would appear that the police were fine in getting a warrant rather than a subpoena. On the other hand, if the warrant was issued to prove the receipt of stolen goods, then the blog / Chen could be protected.
Here's my take on it:
1) yes
2) The Privacy Protection Act protects them from disclosing sources, it does not apply if there is a reasonable belief that the "journalist" committed a crime. Otherwise everybody under the sun would start their own blog and say they received <insert stolen item> from a source and they are protected from prosecution.