Coincidentally, that issue is mentioned in this week's parsha.
The Baal Haturim here says that the connection between Shoftim and the end of R’eiy, which talks about the Regalim, is, as Reb Avin says in the Gemara in Kiddushin 81a, in the sugya of yichud, “sakva d’shatta rigla,” that the worst time of the year (for people getting into trouble with the opposite sex) is during the Yamim Tovim. Therefore, as the Rambam in 6 Yomtov 6 says, “it is the duty of Beis Din to appoint ‘shoftim’ during the Regalim to circulate and to check gardens and orchards and riverbanks so that men and women shouldn’t gather there to eat and drink and come to sin.”
Rav Shternbuch here says that a community should have shotrim walking around during weddings to make sure that there's no hanky panky going on. Talk about a Hechsher Tzedek...
The question arises, however, whether the Morals Police should carry lethal weapons, like the American police, or perhaps truncheons and whistles, British Bobby style, would suffice.
The answer is found in Rashi, who says that the Shotrim carry sticks and lashes.
The truth is that it is easy to make fun of the concept of Taliban-style enforcement of public virtue, and the tznius squads usually end up composed of two types: the sexually repressed in misogynistic reaction formation/over-compensation people, and wild-eyed burka people; but we have to remember that our Torah, and our tradition from the Gemara, from Rashi, from the Rambam, and from the Baal Haturim, teach us that this is something that a Jewish community should aspire to. Theoretically, a sensitive application of this concept in a religious community would be a good thing.
Of course, the first reaction of many 'modern' Orthodox Jews is that they go to mixed dancing weddings, and to the beach, and “lo allah be’libam davar,” that no inappropriate thoughts enter their minds. This might be true (it's not); but this is not evidence of innocence. It only illustrates the callousness that comes from habituation, and such a state is as pritzusdik as actual hirhur. People need to realize that there is a concept of societal public modesty--Das Yehudis--that means that people are not used to frivolous social contact with the other sex. True, the result of such modesty is that hirhurim are more easily triggered; an exposed ankle was scandalous for the Victorians. But considering society as a whole, this is a better condition than being so inured to contact that it becomes insignificant.
A cousin of mine, in Israel, once said to me that yeshiva bochrim think about girls more than modern boys. I agreed that even if this were true (it isn’t), the rate of premarital pregnancy and venereal disease is probably lower among Yeshiva Bochurim and Beis Yaakov girls than it is among her Tel Avivian friends. Or, as a lawyer would put it, chronic misdemeanors are not the same as an occasional felony.