Jacob Kastrenakes for The Verge:

Online harassment is a serious issue that any network needs to deal with, period. And flexible tools like a custom banned word list can let individual users take matters into their own hands to clear up their comments section, should someone begin posting hateful or otherwise offensive or tasteless remarks.

In my experience as a single white male, the harassment on Instagram is far less frequent than on other social networks. That said, it’s a smart move by the company to get these sorts of things in place before issues get out of control.