It's true!

Many textbooks, online research guides, and other resources claim that a .org domain name is an indicator of credibility.
The common explanation is that only non-profits, professional associations, and other organizations are able to register a .org domain name.
Unfortunately, this simply isn't the case. The reality is that there are no restrictions on .org domain registrations.
Anybody with about $15 to spend each year can create one. Hell, that's what I did.

Just take a look at some of these websites that have .org domain names, but shouldn't be relied upon as credible sources:

Educate Yourself, a website promoting various conspiracy theories, has a .org domain name
4chan
4chan, often regarded as the Internet's hate machine, has a .org domain name
Immediate Safety, a fake news website, has a .org domain name
The Pirate Bay
The Pirate Bay, an index of bittorrent filesharing downloads, has a .org domain name
Addicting Info, an left-leaning news and blog website, has a .org domain name

But I was always taught otherwise!

There's a pretty good chance that you've received inaccurate information about .org domain names at some point.
When the Domain Name System was first created (way back in 1984!) .org was in fact one of the initial Top Level Domains.
In fact, in the beginning, there were only six Top Level Domains! What a simpler time...

.ARPA

The current ARPA-Internet hosts.
This domain name arose from the historic development of the Internet, and its predecessor ARPANET. The use of ARPA as a Top Level Domain was only temporary, until its hosts selected some other domain.

.GOV

This domain was originally intended for any kind of government office or agency. More recently a decision was taken to register only agencies of the US Federal government in this domain. State and local agencies are registered in the country domains, which were developed in the 1990s.

.EDU

This domain was originally intended for all educational institutions. Many Universities, colleges, schools, educational service organizations, and educational consortia have registered here.

.COM

This domain is intended for commercial entities, that is companies. This domain has grown very large and there is concern about the administrative load and system performance if the current growth pattern is continued.

.MIL

This domain is used by the US military.

.ORG

This domain is intended as the miscellaneous TLD for organizations that didn't fit anywhere else. Some non- government organizations may fit here.

The original list of domain names is from RFC 920. However, I've used the descriptions from RFC 1591 because they're a little bit more detailed.

But then everything changed.

Well, not really.
There actually never were any formal restrictions on .org registration. It always was designated the "other" category, for websites that didn't fit into the category other domain name, such as .com or .net. And of course, domains such as .edu and .gov were always off-limits to most.
As the Internet grew in popularity, it just so happened that many non-profits and other "credible" organizations did choose to register .org domain names. This may be where the false notion of .org meaning credible began to develop. I don't think it was done maliciously. In fact, since so many genuine organizations were using .org domain names, it makes sense why this belief became so popular.
Of course, the real problem is that a lot of schools started teaching students that when evaluating online sources, looking for .org in the domain name was a method to determine if a website was credible. But this just isn't true! The presence of a .org does not automatically make a website more credible.
And even worse, I believe that teaching people to look for .org as a sign of credibility can be incredibly dangerous. Instead of teaching critical thinking skills to carefully evaluate a source, it falsely claims that there's an easy way to determine credibility.

Well shoot.

It's okay! Hopefully by now you've begun to see the error of your ways.
Now, more than ever, it is critical that we teach everyone to think critically about the web content that they consume.
There are no hard and fast rules that will readily determine whether a website is credible. Indeed, teaching people that they can simply look for .org in the URL and immediately accept a website as credible can do more harm than good.
Instead, we should be providing everyone with the critical thinking tools they need to evaluate and assess sources themselves.
And that starts with simple things like this.
Stop teaching people that .org is a sign of credibility!

Spread the word!