Yet pornography continues to spread it's roots, flourishing at the cost of many other art forms. The problem lies in what pornography really is. Modern day language definitions reflect the issues present with pornography easily enough. These definitions have strayed from the original word derivations and are now attempting to encyst more subject matter into the definition, to fit modern needs and situations. This is the root of the problem, the definition of pornography remains untouched with currently vague laws and abstract definitions.
Pornography is simple.
It is no more than to submit or subject to an action or influence of sexual activity for money. It was called being a harlot in days of old, a prostitute in modern reference. It was also referred to as writing of harlots. You say prostitutes are on corners. One of these days legislation and law enforcement might wise up and there will be a lot of arrests for prostitution.