i don't see why people have problem with this, what would be point randomly search old (white) retired woman, what risk she present? pretty much same goes for Eastern Asians, etc.
if you have biggest odds finding terrorist between dark skinned Muslims, then you will search them the most, nothing random or racist about that, it's like saying i won't take umbrella outside when there is 90% chance of rain because there is 10%chance it will be sunny