So who really cares if the information you found on the Internet isn't totally true? Um
how about your teacher?
or your employer?
or how about you when you need personal, life-important information regarding your health, your finances, and your life-style choices?
Authoritative information sources have everything to do with how accurate and credible the information presented is. You need to care who is behind the information you are using, not only as a matter of personal integrity, but also as a matter of personal safety.
What are the author's qualifications? Is the author associated with a particular school, university, organization, company, or governmental agency? Is his or her email address included on the website?
Take the time to find out who is behind the information!