Populist government comments...
It's plain out a fantasy that using weakened encryption... You know what? Lets just to the chase: that giving the government full access to our day to day Internet presence will change much or even helps to stop terrorism.
Because: who's going to monitor all that data? And even if you do manage to monitor all the available data, and perhaps also automatically look for keywords do you really think that those will be used when people know they're being monitored? Do these guys have any idea how easy it is to simply substitute words and phrases so that you're uttering totally harmless things yet with a whole different underlying meaning?
It used to be the number one hobby for some of my friends and me in the 80's (we were 14 - 18) back when we were very busy swapping Commodore 64 games around. Because you also often read stories about copy parties which got raided by the police and all. Of course not realizing that those were parties where people sold cracked software for hard cash whereas we simply copied and swapped whatever we could find.
Even so... We could talk for quite a while on the phone about homework, while in fact we were talking about removing a nasty copyright protection :)
Quite frankly I think Ghost in the Shell - Stand Alone Complex, first season totally nailed this problem of data amounts. At one time they were hot on the trail of the Laughing Man and at even played "Big Brother": relaying and analyzing all the data accessible to them from the Net in order to try and find a trace. As a result several AI's crashed at the result of the sheer amount of data they had to process and it became immediately clear that they could only keep it up for so long....
Even though that was total fantasy of course I still think it does a good job on showing the actual problem with all this.