Everyone is entitled to their own opinions, but not to their own facts. We may argue over whether the Metric or Imperial system of measurement is better, but no one can deny that a foot is twelve inches or one hundred centimeters make a meter. Introduce your students to the scientific method, responsible journalism, or general critical thinking by using these charts to designate whether given statements are independently verifiable, or just a personal belief.
Isn't it interesting how people can look at the same facts and hold different opinions about them? At least you'll be able to tell which is which.