Dear God, people. We are blessed to have the Internet, which is a source of both information and misinformation. It is usually not too hard to figure out which is which. If push comes to shove, see if you can find a matching reference in two different sources with different biases, because Wikipedia is just too easy to mess around with on contentious subjects. Consider viewing "fact checking" sites with an eye toward their biases.
And if you do all of this, you might actually manage to get your post to be correct on subjects of fact. This is a good first step towards getting people to take your opinion seriously, because -- as many people have noted -- you are entitled to your own opinions, but not to your own facts.
Sadly, many of the people who have noted this don't seem to get their facts straight before posting.