I have decided that my new ultimate pet peeve in writing is people using “formally” when they mean “formerly.” It takes the place of the equally annoying use of “of” in place of “have” (as in, “should of”).
Both of these errors seem to indicate a purely aural (as opposed to vocabulary/grammatical) way of understanding language. Which is OK for an average person; I’m not trying to be an obnoxious pedant. I don’t care so much when I see these errors in informal writing, but when you’re paid to write for a reputable (?) publication, you should know better.
Then again, this issue maybe only happens online, where these supposedly reputable publications a) don’t pay their writers enough to spend time polishing their work before submitting it, and b) don’t bother running these posts past editors before publishing.