Sickness? I'll not use that term to describe what these vermin do. Labeling it an illness is the first misstep down a very jagged staircase. It's no more a disease than robbing banks or carjacking. You will never get me to believe that these things don't know that what they are doing is wrong....and just evil. They should get out of prison at the same time that thier victims recover from thier harm. Never.
Have you looked at the sites to see how many offenders are in your neighborhood? I live in CA, and it's very disturbing. I know that some of these people are victim of circumstance: "she said she was 18" type thing. It happens. But if even if you take away 10% of the number on the site....omg.