I suppose there is generally a distinction between actually doing something and doing it in order to represent it "artistically". Suppose for example that I set out to cheat passersby by operating a scam; then if I am caught I may be prosecuted and sent to prison. If I act in a movie in which I do exactly the same thing, I would not be charged since although I am being paid to represent something in itself illegal, the representation is not itself illegal.

None of this of course suggests that it is a good idea to have laws against prostitition.

Is it true that all states in which prostutition is illegal also legally permit the making of hard-core pornography in which performers are paid to engage in sex with each other? Surely there are some states that prohibit prostitution but do not ban (or at least do not prosecute) the making of pornography (California). But there also might well be states that prohibit both prostitution and the making of pornography, and prohibit the latter using the laws against the former. We need to do some legal research. I know that one feminist legal argument that tried to bring legal pressure to bear on pornography, without going the controversial route of the MacKinnon-Dworkin Ordinance back in the 1980s and 1990s, emphasized that the making of much pornography involved prostitution and hence could already be prosecuted under existing state laws. I do not know whether any jurisdictions capitalized on this argument in fighting pornography (either from a feminist or socially conservative perspective). Another complication is that in many jurisdictions prostitution is merely a misdemeanor and laws against it are rarely or infrequently enforced. That lack of zeal might explain why pornography can be made without legal worries. The making of pornography is also less visible---carried out indoors, and in private places---than streetwalking-style prostitution, and may evade prosecution that way, too. The philosophical (analytic and moral) questions (versus the legal ones) about the relationship between prostitution and pornography are also interesting. I took a stab at it 20 years ago in my Pornography (Yale University Press), especially pp. 127-35.