The SCOTUS generally doesn't comment on cases they don't accept. At best it's a comment on issues with the challenge's standing. This isn't a nefarious scheme. This is judicial normalcy.

I know the explanation : NSA to judges : Here's all the dirt we have on you, bring us down, we bring you down.

They could. But they wouldn't because they observe limits and have effective oversight. Right?

See no evil, hear no evil. Except for the NSA - they see and hear everything ...

Without explanation seems to be how most things are declined. Notwithstanding the headline news, is this somehow unique (to this case)?

The justices gave no reason for rejecting the group’s petition, but the unusual procedure of bypassing the lower courts probably played a role. Other, more conventional challenges to government surveillance programs are pending.