Would you say passengers like Reid and Abdulmutallab were not "risky"?
Yes, but even B- utilization of available intelligence would have kept them off aircraft in the first place. My gripes with TSA policies/procedures are both principled and practical.
On principle, I find the erosion of civil liberties abhorrent, unnecessary and ultimately very dangerous. From a practical perspective, though, Washington has to wake up and realize that what is going on in airports is no substitute for obtaining or making use of available intelligence to know whom shouldn't be on US-bound airliners in the first place.
As the aftermath of Abdulmutallab demonstrated, every piece of the intelligence puzzle was there and in all likelihood one (low level) guy making one phone call to another (low level) guy would have prevented the whole thing in the first place.