There is a certain type of person out there that gets really worked up when grammatical rules are broken or bent.  Years back, Lynne Truss had a breakout hit with Eats, Shoots, and Leaves, a book that demonized bad grammar, poor punctuation, and general awkward phrasing.  Those Grammar Avengers ate it up, but they weren't all adults: these people start young.  Heck, when I was in high school, me and my buddies were very much like this, and some might say I still am.

For a certain type of boy, language books like this are actually a lot of fun.  A recent example stands out as a fascinating tale of grammar-hunting gone mad:  The Great Typo Hunt, by Jeff Deck and Benjamin D. Herson.  In a trip across the US and a brief sojourn into Canada, the authors and friends seek out and attempt to correct grammar errors in signs, posters, and billboards.  They explore shopping malls, restaurants, government offices and national monuments, making whatever corrections they can, and not all changes are welcome.

Other books on grammar and poor application of language are the novelty book series "Signspotting".  These are collections of signs from around the world that are, misspelled, badly translated, or just weird.  engrish.com and failblog.org also feature such uses and abuses of language.  These are along the same lines as F in Exams.

There's plenty more out there, too.  Just check out any facebook post.