>>>This doesn't mean people are being prohibited from drinking or smoking. Gas stations, drive-through restaurants, porno shops (especially porno shops! <g>) and many other kinds of businesses are prohibited from selling in specified locations or venues -- this does not amount to preventing anyone from buying these products.

Actually it may. Recently in New York a zoning regulation designed by a municipality to limit the locations of porno shops was set aside for that very reason. The Court found that the particular limit was so restrictive that it effectively prohibited the shops from existing anywhere within the municipality. (This same regulation was upheld in another municipality because its application in that city was much less restrictive).