The FBI has shrugged off growing congressional anxiety over its surveillance of US citizens, claiming such programs could have foiled the 9-11 terrorist attacks and would prevent “another Boston”.
Pilots exercising their second amendment rights would have foiled the 9-11 attacks, with a total cost of $1.50 in ammo.
FBI chief Mueller says spy tactics could have stopped 9/11 attacks | World news | guardian.co.uk
Spying on the Des Moines knitting club, will apparently keep the FBI from ignoring repeated warnings about Islamic terrorists from foreign intelligence services.
Real Science 
Now, now, we can’t profile! Knitters in Des Moines can easily be a front for Islamic Jihadists and we need to keep an eye on them.
Yet the Boston Bombing slipped under their radar anyway.
Perhaps they need even more information to their job? Rhetorical question.