You can. You should. You must.
That simple formula describes the course of decadence in modern society. First, the formerly unthinkable sins become allowed, sometimes still frowned upon, but yet allowed because of the greater good of individualism, free expression, skepticism over the legitimacy of moral authority, etc. Of monumental help here is the involvement of key authorities: educators, physicians, government leaders, film stars, and late-night comedians.
But then (and often very quickly), the culture gets comfortable with the presence of the formerly unthinkable sins in their midst. The justifications for their practice begin to evolve into encouragement for a wider audience to join in. Freedom from past restraints! Experimentation with new thrills! Expansion of the possibilities of pleasure! Mere tolerance of the formerly unthinkable sins now morphs into a call for general participation.
And then the next phase -- developed primarily to deal with those retrogressive individuals clinging to outmoded ideals, tired religious values and the like -- coercion. It would have been preferable for such people to have been successfully re-educated in the new ways. It would have been so much easier for all concerned had they got with the new program and embraced the "You can and You should" objectives. But they didn't and now, whether the reason is cultural, religious or just plain stubborness, the enlightened powers of government must be utilized to force compliance. It's all for the good...trust us.
This is what's called "social progress" and in the last couple of generations, we have witnessed the "You can, You should, You must" progression in matters of immodesty, public indecency, premarital sex and cohabitation, adultery, drug use, homosexuality and other sexual deviancies, prostitution, eugenic abortion and sterilization, genetic manipulation, and more.
This story from Holland is but one more sad example of the trend.