There are also a number of extenuating differences between his Baltimore example and PRISM, the most critical being that the recording of data in Baltimore was limited both in time and scope by the case it was being collected for. Presumably once the investigators either caught the culprit or gave up on doing so, the payphone taps were removed. They also were only allowed to tap phones they thought might be relevant to that particular investigation. The war on terrorism used to justify mass wiretapping, on the other hand, will literally go on forever and relevant data could be anywhere. Terrorism is not an enemy that can plausibly be captured or defeated (like a drug dealer or the Nazis), nor is it localized to a few city blocks or ISPs or websites, therefore there is no limit on how long this data will need to be collected for or what sort of data might be required.

I'm all for brief and limited surveillance authorized by warrants tied to a specific case (e.g. his Baltimore example), what I find unacceptable about PRISM is exactly the thing Simon glosses over as irrelevant, its scale: virtually unlimited in both duration and scope.