ECPA reform campaign will get official White House response
ECPA, while forward looking for its time, became law in 1986. This was long before many of the services we use today, including email, cloud services, or Facebook even existed. As it stands the IRS, NSA, and hundreds of other government agencies can read your electronic communications and data without a warrant.
If you want learn more, our friends at the Center for Democracy and Technology have put together a great resource page.