Here are some reasons why I believe this proposal is important, appropriate, and why it would help improve our country. Here are some answers to some common objections I anticipate.
* The reason PRISM scoops up all US communications, they say, is simply because the majority of world communications pass through our computers even when sent between people outside the US. This is certainly true of financial communications.
* The reason PRISM proponents say that the eavesdropping overrides privacy concerns, such as the 4th Amendment, is because terrorism costs lives, threatens the security and stability of entire countries, and is one of the most illegal activities on the planet. Even though many sophisticated financial frauds exist in legal gray areas... rate-fixing, bid-rigging, and many similar practices are also blatantly illegal. And as their damage piles up to tens of billions of dollars in the middle of a worldwide recession, surely these activities are also a clear and present threat to the security and stability of communities, industries, and even entire countries, including our own. Arguably this threat is even more important than the threat of terrorism, which while heinous and shocking, is far more rare. Fraudulent financial communication over electronic networks occurs virtually every hour of every single day.
* PRISM proponents claim that nobody's privacy is violated because their computers look for patterns to link individual communications to a larger pattern of suspicious activity. Supposedly PRISM will only pinpoint communications relevant to the crime of terrorism. If anyone is worried about the privacy and security of their financial transactions, surely the same protection applies when we start examining fraudulent financial communications such as rate-fixing and bid-rigging. Furthermore, terrorism experts claim that clamping down on terrorist financial networks is a big part of eradicating terrorism, so there's a place where the two crimes, bank and investment fraud versus terrorism, have common ground. Anyone who supports fighting terrorism "by any means necessary" yet is simultaneously opposed to the government peeking into _your_ investment accounts and checkbooks... you should know: the government is doing this already.
* PRISM supporters claim that it's necessary to vacuum up all communications from everybody they can monitor, because suspicion is only confirmed by analyzing a diffuse pattern of individually trivial actions or communications. For example, it's not suspicious to rent a car with cash, and it's not suspicious to buy fertilizer, but if you do both on the same day, the terrorism experts sit up and take notice. The financial crimes that have devastated the entire world economy since before 2008 work in a similar manner. There is virtually never an e-mail where a powerful investment banker says "I want the LIBOR interest rate to plunge five points before Tuesday". There is almost never a smoky cigar-filled back room where corrupt bankers collude to say "Let's sell crappy mortgage tranches to retirement mutual funds". These problems only manifest as a pattern, which is usually composed of dozens or thousands of calls and e-mails saying "You scratch my back a little on your draft LIBOR report and I'll cut you a deal on some great mortgage tranches". The systems and pattern analysis capabilities of PRISM seem ideally suited to identify these financial crimes like rate-fixing and bid-rigging, which also appear only as a diffuse pattern of individually trivial actions and communications.
* One reason people say that the SEC is so ineffective at preventing or even prosecuting sophisticated financial fraud, is because it's understaffed and lacks sophisticated understanding of the financial manipulation. That is the weakness with the SEC which this proposal hopes to address. With just a tiny amount of inter-agency co-ordination, and a few extra processing runs on existing computers, the analysis power of the SEC could be broadly expanded at a stroke, at a negligible cost to the government. Furthermore, much of the SEC's lack of understanding is merely because it can't keep up with the private financial companies' technology, for example in the case of high-frequency trading. Giving the SEC access to the sophisticated NSA computers and the computer analysis algorithms used for national security, would go a long way towards neutralizing that disadvantage.
-- More reasons may appear in this post as time goes on.