It's important to understand the reasons and consequences for the laws skyDancer referrs to.
The human body is biologically capable of producing children many years before the two people that created the child are capable of caring for it. The laws also consider that older people are capable of manipulating children into doing things that they will be very sorry they did later in their lives. The laws protect children until they have matured enough to understand the consequences of what they're deciding.
The consequences for the older person are also important. If you are convicted of being a pedophile, you will serve time in a penal facility where the other prisoners are very hostile toward pedophiles and once you get out, your name will be on a public sex offender's list for the rest of your life.
The bottom line is, when either or both of you are below the legal age limit, having sex is not only bad from the standpoint of the law, it can be life changing for both of the people involved.
Answered Feb 28, 2011
Edited Feb 28, 2011