Random security checks

Random backpack checks and frisking...Random as defined by uniform probability distribution wherein chances of being frisked are independent of race, skin color, name structure and facial profile. Thats what the declared intention is..but people are suspiscious that a particular segment is picked more randomly for these checks....It's easy to take me for a Puerto Rican, but my name being so non-hispanic, I am always pre-selected randomly for a detailed security check while taking domestic flights in US...But I think thats how it should be, cause the security threat is of that nature...Would one, for some instance, insist that India have the same level of intelligence coverage in Nauru as much as in Pakistan...The logic is simple..if past experience shows that people having a certain physical profile have been responsible for insurgency, then it's only rational to keep a more watchful eye on that particular segment....
However, security agencies in US, UK etc. have played to the politically correct gallary and publicly insisted that the searches are really random...while in practice there is every evidence that its more random for some..
Also, I have no idea how retina scans and finger-prints taken during immigration are going to be useful in enhancing security...As per some reports these measures may increase potential misuse of the collected information.....Somehow one gets the feeling that things are being done just to show that something is being done.