Mostly only illegal content should be removed.
Did you read the article? Removing illegal content (like how to make a bomb) is a censorship, because sender and receiver are happy with it. We need to bring arguments like "the good of a society" to justify removing illegal content.
But harassment, threats and suchlike no one wants to get. Sender may be happy to send it, while receiver is not happy to receive. We need not to resort to a good for a society explaining, why these should be banned.
How many people like getting criticism of any form? Should we ban all criticism?