Decius wrote:

If a person stores documents in her home, the government may use a subpoena to compel production of those documents.

After a lot of digging and a couple of email exchanges with law profs my understanding is that the 5th Amendment would afford you some protection against subpoenas of this kind, provided that the government did not know exactly what was looking for, which you would not be afforded in the context of a third party email provider. Here is the full quote in context:

Current law allows for the acquisition of certain stored communications using a subpoena where the account holder receives prior notice. This procedure is similar to that for paper records. If a person stores documents in her home, the government may use a subpoena to compel production of those documents. Congress should consider carefully whether it is appropriate to afford a higher evidentiary standard for compelled production of electronically- stored records than paper records.

The problem with this position is that it ignores the fact that under current law the 5th amendment would come into play in this "documents in her home" scenario but not in the third party email provider scenario contemplated by the ECPA. The absence of that protection in the third party context is one of the reasons that additional regulation, such as the ECPA, is needed. IE - the higher evidentiary standard is needed to offset the lower particularity standard.