I should've made an effort to make two distinct points:
1) killing someone over circumstantial evidence alone is questionable
2) killing someone based on unilateral interpretation of any evidence (as opposed to the result of a verdict from a court) is questionable
Other than that: Are you seriously arguing that it is harder to verify if someone conspired to defraud, assuming the NSA could provide rich evidence of both communication and content, than it is to prove that someone is conspiring to do harm?
That is: in the latter case you (would/should) have to prove intent before any crime is committed (and that a crime is likely to be committed) -- while in the latter case you would only have to be able to document the most likely path that led to recorded events taking place? You're even able to document profit, in the case of the banks.
I agree with your points 1 & 2. It's questionable.
to the other point, yes. Securities laws, from what I can tell, are very convoluted. Even experts find it hard to tell when one enters or exits the grey areas. In addition, in 2008, there were other considerations to take. Until, I know better, I don't think the NSA is allowed to use whatever information they have, to prosecute domestic crimes. They may 'tip off' the SEC, etc. but the SEc must gather their own info and evidence. Also, it's not as if the NSA are experts in Securities. They look for physical threats rather than soft threats to the economy/population.
That is: in the latter case you (would/should) have to prove intent before any crime is committed (and that a crime is likely to be committed) -- while in the latter case you would only have to be able to document the most likely path that led to recorded events taking place? You're even able to document profit, in the case of the banks.