We were at PetSmart yesterday, and I happened to spy one of my least favorite grammatical errors: the use of a plural where a possessive is called for and vice versa.
To be fair, this appeared in a tag engraving machine, so it really wasn't PetSmart's mistake. However, some well-meaning but semi-literate PetSmart employee, obviously attempting to follow the Law of Conservation of Apostrophes ( "For every apostrophe omitted from an "it's'' there is an extra one put into an "its"), hung this sign about three feet away:
When I see mistakes like these, made by adults who have, presumably, completed elementary school, I can't help but echo the sentiments of Lynne Truss in her wonderful book Eats, Shoots, and Leaves: "Why did the Apostrophe Protection Society not have a militant wing? Could I start one? Where do you get balaclavas?"