This is a very interesting point Freda. You might assume as much testing as possible would be undertaken in an effort to have as clean & safe a sport/industry as possible. Most people know - the more effort you put into testing/detecting/investigating - the more you will catch (in the initial stages at least, before the message/consequences hit home).
But it could also be a case of be careful what you wish for.
I know of a Police officer who was expert at apprehending drink drivers. Nothing sneaky or underhand - all standard stuff - just dedicated to road safety and seemed to have a real knack for catching them. I thought the officer's bosses would be delighted - but in fact there was some talk the officer, by prosecuting all these drivers, was making the campaign to reduce drink driving look ineffective. Soon after the officer was moved to other duties.
So I am left wondering as far as drugs in racing - just how effective do they want to be in detecting drug use by the participants - and could they handle the outcome if they went hard-out??
J.