Is speaking a certain language a crime? Even an artificial one? Unfortunately, it occasionally is.

Something I've soapboxed about before is how people often deride Esperanto as a bunch of dumb hippies trying to bring about world peace through a made-up language and failing miserably. This bothers me partially because, in the broader context of conlang history, Esperanto was wildly successful, even if it didn't meet its initial goals, which people tend to underestimate.

But more than that, people tend to overlook (or more accurately, be completely unaware of) the persecution that Esperanto speakers have faced. Thousands of people have been killed by their governments, and many more arrested, for speaking a language that their leaders disapprove of the language, and the movement(s) associated with it. Anti-Esperanto violence has often been interlaced with anti-Semitism (as Ludwig Zamenhof, the language's creator, was Jewish), economic motives (fear of communism, fear of bourgeois influence, etc.), and other general authoritarian reasons. I've written a bit about this in a couple older answers, linked below:

How were Esperanto speakers treated in the USSR?

But the honeymoon never lasts forever, and some discontent among Esperanto letter-writers led to Soviet suspicions that the SEU [Soviet Esperanto Union] was trying to bring in bourgeois ideas toward the end of the decade. As it turned out, some Esperantists weren’t a fan of living in Soviet Russia, and made that clear to the foreigners they wrote with. Esperanto also clashed with Stalin’s own post-1929 plans for a world language. Tensions escalated both among disparate Esperanto groups in Russia, and between them and Soviet leadership, and long story short, the Soviets stopped trusting the Esperantists, or any other alternate ideology. By the end of the 30s, Esperanto clubs had been shut down, magazines were cancelled/censored, and of course, the purge happened, [SEU leader Ernest] Drezen included among the many victims. Esther Schor recounts for us (190):

The onset of the Great Purge in 1936 found the SEU keeping a low profile, publishing theories of language pedagogy and advertising its usefulness to foreign-language instructors. But once the purge began in earnest, Esperantists were persecuted as individuals with suspicious ties to those in other countries. One by one, the luminaries of the Soviet Esperanto movement disappeared from view. Rank-and-file members were also arrested, interned in labor camps, and killed. Precise figures are hard to come by; one soviet Esperantist estimated that upwards of thirty thousand samideanoj [fellow Esperantists] were arrested and several thousand died.

Did people try to replace Esperanto in Nazi Germany with another IAL?

Throughout 1935 and into 1936, Esperanto organizations were liquidated and later prohibited, members of such organizations were banned from the party, a number of Esperantists were arrested for treason, and the state started working on propaganda against the language. Lidia, Zofia, and Adam Zamenhof, Ludwig Zamenhof's children, were among the many Esperantists who were killed in the Holocaust. Like I said earlier, the language was too heavily associated with leftist and pacific and Jewish movements; nothing GEA [German Esperanto Association] and NDEB [New German Esperanto Movement] could do would strip the language of those qualities in the eyes of the Nazis, and so it had to go. Private correspondence in Esperanto was necessarily forbidden, but enough Esperantists were causing trouble for the Nazis that they were all under suspicion and prone to attack. By 1940, Esperanto as a mere language was considered to be a "weapon of the Jews" (qtd. in Lins 131).

Frankly, I feel like when so many people gave their lives to this language—or, more accurately, had their lives taken from them—we ought to treat Esperanto and its speakers with a little more respect than is often granted them in mainstream discourse.

Sociologists regularly talk about "the great crime decline," the phenomenon in the United States by which murder rates roughly halved between 1991 and 2014, and cities became very, very different places -- safer and less segregated (in some ways), argues Patrick Sharkey. Note: most of this decline occurred before 2002, thus remaining in-scope for the sub.

The catch? Nobody knows for certain why it happened. Not in full, at least.

There's no trigger event that took place in 1991 that set off this massive decline in violence; most popular explanations (the so-called "1994 crime bill") post-date and otherwise don't explain the trend. Analysts have ruled out some explanations and speculated about others -- de-leading of gas and legalized abortion are popular ideas referenced in the press -- but these are hotly debated, and look worse as new evidence emerges.

I find this both fascinating and surreal. American life today is wildly different than it was in the 1990s, in part because of a historical change that we don't fully understand and may never comprehend. It's also a poignant lesson in the complexity of history. Social phenomenon like crime are determined by any number of other factors, environmental, political, and historical, and tough to reduce to simple explanations.

Social crime and community punishment is quite interesting in early modern Britain. Social crimes ranging from the scurrilous, such as gossiping and scolding, to the serious, such as witchcraft, were policed by the community. Perceived inversions of societal norms, such as adultery or the domination of woman over man could be punished by public humiliation of the couple, often in the form of charivari, loud mocking demonstrations that acted both as a shaming mechanism for the offenders, but also as a reinforcement of the norms that they had transgressed. In early 17thC Wetherden, after Nicholas Rosyer was beaten by his wife, the charivari was so humiliating that the couple ultimately fled the town, their reputation in tatters.