This is not limited to the general public. People who make their living through the English language lack knowledge of the toolbox of their profession. A good example of this is this story, in which it is reported:
Most of the fish were mullet, ladyfish and catfish, and not the valuable sporting fish called snook that died in mass during a cold spell last year.
The phrase is not "in mass," which would imply that they died during worship services in a Catholic Church, but rather "en masse," meaning that they died in a group. Also, there should be a comma following the word "ladyfish."
Also, I would point out to all that:
"Your" is possessive, as in "Is this your blog?" , while "you're" is the contraction of "you are"
Possessive pronouns like "its" "Yours" "his" and "hers" do not get an apostrophe.
"Breath" is the word that rhymes with "death" and is a noun, as in: "He has bad breath."
"Breathe" is the word that rhymes with "seethe" and is a verb, as in: "He is choking and cannot breathe."