This has nothing to do with data streams but with offline hash attacks......e.g. someone hacked and stole user account data and and wants to brute force attack.
1024/2048bit key encryption is far harder and as yet have not been broken. The minimum bit length today is 2048 for keys.
Your data can also be easily protected if you use AES-256 to encrypt and send anything as I don't believe its been shown to be broken yet either.
The complicated issue regarding warrants and searches is somewhat addressed here:
»
www.reuters.com/article/ ··· 20121117