I think I might support this, but I'm not done thinking about it.

One thing that would happen immediately: people would stop discussing marital affairs via telephone. (And there'd be a brief spike in murders if the historic data were released!)

The knee jerk reaction is to extend that idea to would-be terrorists, too--to imagine that they'd simply change their communication habits (they already try to avoid monitoring, I presume).

But, let's think a little harder, and let's start with the married folk.

Bob and Mary are married. Eve is Bob's co-worker. Don't you think that Eve-Bob communication is going to contain some tell-tale signs _before_ the affair? Could Mary (or Bob, or Eve) use this information to prevent the affair (or proceed in a less painful manner, depending on their situation)?

I was interrupted and now I've put that line of thought on hold and developed a new one.

Remember IRC? Did you ever choose your stance in a dispute by reviewing the logs? ...Was there anything wrong with that? Wasn't it generally helpful?

Of course in that world, PRIVMSG does exist. In our world, it doesn't.

I dunno.