There are some really damaging cases, like an 18-year-old having sex with his 17-year-old girlfriend and the girlfriend's father insists on pressing charges. Now the kid is not only labeled a sex offender for life, but his listing says victim was a minor. Our whole approach to criminal "justice" is deeply flawed. Recommended reading: Are Prisons Obsolete by Angela Y. Davis: http://www.amazon.com/exec/obidos/ASIN/1583225811/donhosek
Yes, there's been a few of those cases - absolutely ridiculous. I think there was legislative change around that (maybe in Aus?) whereby if both participants are under-age or close to under-age, they don't record convictions.