A quarter won't buy you privacy in Philadelphia. \n Private video booths showing adult movies have been banned in Philadelphia, Pittsburgh and every other burg in Pennsylvania. The state supreme court ruled that a state law requiring well-lighted "open viewing booths" is not in conflict with the First Amendment and therefore may be enforced. \n A group of adult entertainment establishments challenged the law in a lower state court last year. The group argued that the law violated First Amendment rights because, among other things, it placed restrictions on certain types of expression that were not placed on other types. \n Nonetheless, the lower court upheld the validity of the law and the state high court affirmed the decision. \n Adult stores believe they will lose customers who prefer to watch porn movies in private. From now on, all viewing must be done out in the open, which will undoubtedly limit the enjoyment some viewers got when doors could be closed or curtains drawn. \n Commonwealth Court Judge Bonnie B. Leadbetter acknowledged that customers might prefer seeing peepshow videos in private. \n It doesn't matter, she said. Sexually explicit material may be put in a different class than other types of speech and expression and, as such, doesn't enjoy the same protection. \n Also, the judge said, the purpose of the law was not to stifle free expression but to discourage people from committing sexual acts and engaging in prostitution, which can lead to the spread of communicable diseases.