It should remain within the law.
There are adequate provisions for the security service to monitor data these require warrents from the Home secretary.
I don't believe Theresa May would be shy in authorising them.
If there is a problem getting these warrants then that debate should be had.
We cannot have security services acting outside the law because they find following the law inconvenient.
That applies in the US and the UK- it sounds to me as if the NSA have shared data that they have obtained under the Prism program - which I suspect is illegal under US law.
I don't know whether we can blame our security forces for accepting this information as they didn't gather it, it is probably legal.
But the US need to put their house in order.
The touchstone for me is whether security forces have acted outside the law - the law is too restrictive is not an excuse - if they need more powers they have to ask for them and the law needs to be ammended