The number of requests is not, as Obama asserts, "surprisingly small". It is probably smaller than it ought to be, and in light of the NSA's recent admission that they've tapped warrantlessly, that's probably the explanation.
If there's a reason that Obama can't confirm it (beyond that he just doesn't know), it's because it is believed that the FISC acts differently than other warrant-granting entities in that at least usually, when it denies a request, it also then provides guidance on how to refile the request in a way that it might be approved. Regular courts will do this on procedural errors, but not as a matter of course.
In all likelihood, the 11 denials the FISC has issued over the past 34 years were likely all later converted to approvals with their guidance.
Don't we have evidence why the number of requests is "surprisingly small"?
All this time we assumed that the requests would refer to individuals who were under suspicion. But the Verizon order tells us differently. Here we've got one, giant request for "every call that passes through Verizon".
It's a huge amount of spying being done, all carried on the back of one (or a handful) of blanket requests.
As I understand it, that's possible, but the 'metadata' requests aren't routinely surveyed because they don't capture 'enough' data to constitute something that would require a warrant.
To put it in more real world terms, it takes a warrant for me to go into your house and listen to what you're doing, but I am perfectly free to sit outside your house and watch your comings and goings without one. I believe (but do not know) that the current interpretation of the metadata requests is being treated like this, where the NSA simply feels that no warrant is required.
Your argument however, probably holds more weight because, at the least, you would very much hope that Verizon and company wouldn't be handing over data without some kind of warrant, even with a 'strong suggestion' from the feds.
Regardless, here's their record, and they certainly aren't disapproving much. https://epic.org/privacy/wiretap/stats/fisa_stats.html
If there's a reason that Obama can't confirm it (beyond that he just doesn't know), it's because it is believed that the FISC acts differently than other warrant-granting entities in that at least usually, when it denies a request, it also then provides guidance on how to refile the request in a way that it might be approved. Regular courts will do this on procedural errors, but not as a matter of course.
In all likelihood, the 11 denials the FISC has issued over the past 34 years were likely all later converted to approvals with their guidance.