Doping in sports nowadays

Recently Alan Abramson wrote an article where he noticed whether tests conducted by the World Anti-Doping Agency (WADA) were efficacious.
The WADA conducts many tests for steroids and other performance-enhancing drugs every year. It seems that those that apply steroids and/other related medicines are caught. Someone may think that the world of sports and professional bodybuilding will be soon cleansed from usage of banned products. For example, many tests for prohibited preparations have been conducted at the 2012 Olympic Games.
But some questions appear here. Are these tests sophisticated enough to catch any person that dopes? Are these tests efficacious?
Let meditate over results of certain tests. In 2010 the WADA published statistics according which 258,267 samples were analyzed by 35 WADA-accredited labs. Out of these samples 4,820 results represented atypical findings. About 60 % of positives indicated about steroid use. Many positives were for cannibinoids. 10 % positives indicated about application of marijuana. As you observe, only 60% out of those that took prohibited medications applied steroids. Is it real? Don’t show the results of the tests that the WADA doesn’t do the job properly?
The former president of the WADA Dick Pound considers that at least 10 % of athletes that took part in the 2012 London Olympics used steroids. He notes that those steroid users that are not clever are caught by anti-doping agencies. He also notices that a sportsperson who has been caught applying banned medications will fail an IQ test. He concludes that only unwise sportspersons can’t avoid detection.
Thus, when you hear that the WADA has conducted many tests to make sports clean, consider whether these affirmations are true. Can the WADA make competitions fair? Why does the WADA publicize about number of tests?
It seems that the WADA only wants to convince people that the job is done appropriately. The WADA desires to secure future funds. This is the reality.