Reminder: this is their #1 most used tool for collecting data. Snowden told us of the existence of this program under the codename PRISM.
This allows them to download the entire contents of your gmail instantly, directly from Google, without a warrant. Or your iCloud Photos and Backups (complete iMessage history) directly from Apple. No warrant required.
> This allows them to download the entire contents of your gmail
Does it though? I believe they did that with PRISM by eavesdropping on the unencrypted data transfers within Google's network itself - without their knowledge. Since that revelation came to light I presume Google have upgraded their security.
Wait, doesn't the constitution protect people from this?