Censorship is a wide-ranging word, and artists who haven't toed the line and have produced art that goes against the rules have often not had a great time in history. Having your work banned or altered (the "fig leaf campaign" that meant modesty leaves were painted over Michaelangelo's Sistine Chapel is one example) is one thing — but under various regimes in history, personal safety was also an issue.
Many people, when they think of the grand gestures of suppression of art, think of Nazi Germany, but the reality there was more complex than simply burning books. The Nazis had a particular artistic "vision" for the future of their Reich, with acceptable types of art pushing big neoclassical visions and a bucolic Germany full of frolicking Aryan maidens. Art is a key part of state propaganda, and the Nazis took two approaches to it: give big patronages to artists who would toe the party line, and humiliate and terrify artists who didn't. Hence the famous Degenerate Art Exhibition in Munich in 1937, which ran alongside a Great Art Exhibition of "good" work; the "Degenerate" exhibit was filled with modernist paintings Hitler hated. These images weren't burned; rather, they were put in a public arena to be laughed at and made an example of.
For another look at the same issue, take Stalin's Russia. The great composer Shostakovich put on an opera called Lady Macbeth Of The Mtsensk District in 1934, and was horrified to discover that the official state paper, Pravda, published a review called "Muddle Instead Of Music." The suggestion was clear: if Shostakovich didn't produce stuff that was more in line with Stalin's tastes, he was in personal danger. Like many great artists under Stalin, he would balance artistic output and his own neck for the rest of his life. As the great Russian musician Vladimir Ashkenazy explained to the New York Times:
"Not for nothing did Shostakovich's son Maxim, at a rehearsal of the 11th Symphony (''The Year 1905''), whisper in his ear, ''Papa, what if they hang you for this?''"
Serious consequences continue to threaten artists in regimes that maintain strong propaganda rules about art "opposing the state." Russia, with its censorship of Pussy Riot, is one example, as is China, which has censored political art, particularly around Tibet (including at an exhibition in Bangladesh). However, there's a small bright side: one Chinese artist noted in 2014 that it can actually be profitable to be censored, because it brings international outrage and attention.
So what are we to make of all this historical battling between artists, governments and rulers? The Julius Caesar debate is a very, very old one, and is in fact a lot milder than it could be, considering that nobody's getting sent to the gulag, exiled, or sent to jail. But what we should remember, when we encounter controversial art that we may or may not agree with or find to be in poor taste, is that the path of repressing critical art does not historically lead to good things.