Next American City: Jeff Deck travels across the country in search of typos.

The "plural apostrophe". Comma omission. Singular nouns with plural verbs.

In a world filled with signs, we all encounter these kinds of mistakes on a daily basis.

In Next American City, Jeffrey Hill profiles Jeff Deck, a man who's actually doing something about it.

As founder of the Typo Eradication Advancement League, Deck and his punctuation posse have traveled the country searching for misspellings, comma splices and other errata, which he documents on his blog.

However, the 28-year-old crusader is no passive observer - he has been known to copy edit the signs himself using white out, markers and stickers.

It's vandalism with a cause.