It's worth noting that this article by David Simon was written on June 7th, purely in reaction to the leaked information about Verizon metadata being collected. As more information about PRISM became available, Simon acknowledge that the leaks did point to something more serious than he had acknowledged in his original post [1].
With that context in mind, I still think it's worth reading Simon's original post that you linked to. He's a very articulate writer who has clearly shown he's no puppet of the establishment through his work on shows like The Wire.
His basic point seems to be that the government should be allowed to do it as long as we don't hear about any specific abuses. There are two problems. The first is the one he points out: when everything is classified and anyone who notifies the public is subject to the treatment given to Manning and Snowden, even finding out about the abuses much less holding those responsible accountable is extraordinarily difficult. The second problem is that the really bad abuses of an accumulation of power like this are so bad that we can't just wait until they happen before we do anything about it.
He also says some questionable stuff. Like this:
>We asked for this. We did so because we measured the reach and possible overreach of law enforcement against the risks of terrorism and made a conscious choice.
Everyone in Congress who read the Patriot Act before voting on it voted against it. So no, we didn't. We had a gut reaction to a tragedy, somebody pulled a defense contractor wish list out of a drawer and they passed it in a moment of sorrow and anger. The country is only now starting to reach the point that we can have a rational conversation about anti-terrorism without the pain of a recent tragedy allowing self-interested warmongers to goad us into an overreaction, and it's time that we seriously reevaluate what we allow the government to do on our behalf.
And I'm reminded of what John Oliver said hosting the Daily Show when all of this came out: "I think you're misunderstanding the perceived problem here, Mr. President. No one is saying you broke any laws. We're just saying it's a little bit weird that you didn't have to."
In fairness, I don't think that's Simon's point. I think his point is, the government should be allowed to do things like they did on 'The Wire' as long as there is due process, i.e. independent oversight, transparent criteria, ability to change the criteria through a democratic process. And yeah, we did ask for it because we knew about AT&T secret rooms and there was no outrage. Until we demand public hearings about exactly what is going on and what constitutes due process we're still asking for it.
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.
I also disagree with his premise that the data is too big for innocents to be caught in a dragnet. Has he never seen a heat map or a histogram? There are ways to characterize big data that can lead to false positives in the analysis.
Additionally, an easy abuse of the system would be to look for people doing embarrassing things and link it to those people for later political blackmail or other neutralization. We don't have evidence that this has occurred, but I think it was indicated that the audit trails and other civil liberties protections were not implemented well in these systems.
It is well worth a read for an extremely well argued, and informed, opinion from the other side.