SEE HOW THEY SPIN

The defenders of the NSA keep upping the number of successes:

In the days after the leaks, House Intelligence committee Chairman Mike Rogers cited one attack that he said was thwarted by the programs. In the comments of other intelligence officials, that number grew to two, then 10, then dozens. On Tuesday, Alexander said more than 50 attacks were averted because of the surveillance.

I recall that sometimes the British did not act on Enigma intel because they did not want to tip off the Germans. Does the relatively large number of successes mean that Al Qaeda and others have also been tipped off?