Given how many people’s careers have been destroyed on the Internet by the (often unwitting) inflammatory use of words or images, a recent Wall Street Journal article should interest many:
"Straight talk about banned words" by an American Studies prof John H. McWhorter, who writes:

At street level and in popular culture, Americans are freer with profanity now than ever before—or so it might seem to judge by how often people throw around the “F-bomb” or use a certain S-word of scatological meaning as a synonym for “stuff.” Or consider the millions of fans who adore the cartoon series “South Park,” with its pint-size, raucously foul-mouthed characters.
Concluding, he notes,

In other respects, we’re actually quite a bit like our ancestors. We are hardly beyond taboos; we just observe different ones. Today, what we regard as truly profane isn’t religion or sex but the slandering of groups, especially groups that have historically suffered discrimination or worse. More. 
Okay, but one problem isn’t confronted here: Political correctness offences are not just a social punishment. Anyone who was involved in the free speech wars in Canada will know this well: Apart from lives and careers destroyed by law, it wasn’t until we eliminated Section 13 of the Human Rights Act (against “hate speech”) that we could have honest discussions about many issues again.
It is just too easy to shut down needed discussions by claiming that one is victimized by “hate speech.” Or to avoid them for fear of the accusation.
We can call that anything we want, including "social justice." But don’t call it a solution.
A lawyer friend has suggested replacing bad speech by better speech instead. Could that be a good place to start?
Indeed, his “My name is Ezra Levant” has sparked a serious rethink in Canada:

Denyse O’Leary is a Canadian journalist, author, and blogger.