Barb, one of the three protagonists, in THE SLEUTH SISTERS, is into grammar big-time. Some have referred to her as a grammar nazi, but I prefer the term grammar ninja, because Barb doesn't go around ordering people to do as she says. She's pretty athletic too, climbing up to billboards and rooftops to make her corrections.
My editor calls Barb "obnoxious" and "cowardly," because of her anonymous correcting of other people's mistakes. I find it ironic that an editor would say that, but it might be because she isn't allowed to be anonymous. Barb's Correction Events are meant to be funny, since those who recognize the grammatical mistakes of others often have the desire, though probably not the nerve, to fix what's wrong. For most of us, being right about such small things isn't worth the hard feelings it might cause. Barb's method might be the kinder way to go.
Fans have an amusing response to the grammar thread in the books: I get corrected, often with a comment about how Barb should have known better.
News flash, folks: Barb is fictional! It's me who's reading 80,000 words over and over, trying to find that one error that slipped past the editors, the beta readers, and me.
Some of the corrections that have been suggested are correct, and some aren't. Though many of us feel we could be grammar ninjas, some could use a refresher course on things like subject complements, which are supposed to be in the nominative case, despite the widespread use of "It's me."
My own view of grammatical mistakes? Of course I notice them--someone grounded in study of the English language for decades isn't likely to miss errors. But I don't judge people for not caring as much as I do UNLESS it's their job to care. I have no sympathy for public figures who can't match a verb with its subject or those who
speak in disjointed, unintelligible phrases.
For the rest of the world? I'd prefer you don't use puppys on a posted sign, but if the meaning is clear, I suppose it works.
Still, I don't blame Barb for helping you out a little.