[Hemingway's Ghost]

I may own a gun, but can I point it at you, thereby threaten you? No. Prostitution and drugs are an endangerment to my being, my property value, my children's welfare, and my community's quality.

Apples and oranges. In a libertarian (or any) system of laws, your first example is clear-cut evidence of criminal threat. Your second example (prostitutes and drugs) would be prima facie evidence of no crime in a libertarian system---you have to define these behaviors as criminial in order to make them criminal. You're assuming that prostitution and drugs---however broadly you define them---necessarily create crime. In other words, you're not fighting the actual crimes you fear, like stick-ups or drive-bys or what have you, you're railing against what you perceive is the cause of the crime.

Why create bad law? Fight actual crime---a stick-up is a stick up whether or not the goal was to score money for crack or baby food.

[Texaggie79]

I don't fear drive-bys and stickups from the use of drugs or prostitution. I fear a deterioration in my community therefore, ultimately, a threat to mine and my family's well being.

When I point a gun at someone, it does not mean that it will fire. There is a significant threat of harm, just as with the use of hard drugs by your neighbor.