I began learning this back in the newsprint era from letters, and the lesson has continued from emails and comment sections on websites.
Postal letters and emails are outlets that permit a reader to let off steam by lambasting a writer, but comment sections permit readers to share their outrage with all the website's readers in addition to the writer and to gang up on and slander a writer.
Websites, such as OpEdNews and Information Clearing House, that I permit to repost my columns return the favor by having comment sections in which government trolls, assorted kooks, Reagan haters, and uninformed individuals can slander me, assault my reputation, misrepresent what I write, and do their worst to counteract the information that I supply to readers. Trolls and their ilk do the same thing to any number of writers who try to compensate for the absence of an honest Western media. Look at who is under attack. It is not the presstitutes at the New York Times, Washington Post, and Fox News; it is Julian Assange and Glenn Greenwald, for example. One is said to be a rapist, and the other an accessory to the theft of documents.