Ed Felten's final post (number 9) in his series about 21st century wiretapping is up.
"The infrastructure of content-triggered wiretaps is the infrastructure of a police state. We don’t live in a police state, but we should worry about building police state infrastructure. To make matters worse, I don’t see any technological way to limit such a system to justified uses. Our only real protections would be oversight and the threat of legal sanctions against abusers.
To sum up, the problem with content-triggered wiretaps is not that they are bad policy by themselves. The problem is that doing them requires some very dangerous infrastructure.
Given this, I think the burden should be on the advocates of content-triggered wiretaps to demonstrate that they are worth the risk. I won’t be convinced by hypotheticals, even vaguely plausible ones. I won’t be convinced, either, by vague hindsight claims that such wiretaps coulda-woulda-shoulda captured some specific badguy. I’m willing to be convinced, but you’ll have to show me some evidence. "