There is this thing called "age of consent". There is this other thing called "law". They go hand-in-hand.
1. Pedos should be shot if the law provides for such sentences for the successful conviction of similar crimes.
2. 13 year old hos that hang around at parties and drink, snort and have sex may not act like a child, but she is too young to drink, not allowed to snort under any age, and does not possess the legal status to consent to sexual intercourse. Besides, getting drunk, wired and acting like a skank is hardly befitting a "woman's" behavior.

The law doesn't see many things. You know the saying: Justice is blind. And I personally think with countries in Africa where it's perfectly legal for a 50-year-old man to marry a 14-year-old woman (not the recent case in Egypt; I'm talking about other countries) you will always get arguments as to what constitutes a reasonable age of consent. However, that isn't for us to interpret or decide whether having sex at a young age is morally incorrect or not, or whether it should be someone's unalienable right to snort cocaine, or whether or not drinking alcohol brings health-related benefits. The law (in the US) states that persons of legal age are guilty of buggery if they engage in sex with someone under the legal age of consent, possession of cocaine is illegal under any circumstances, and you must be at least 21 to drink - your health be damned.
The law grants, provides and restricts us from our rights. We're not here to interpret or judge the law. We've got executive, judicial and legistative bodies that do this for us. In some cases, unfortunately.