Chicagoing: Graffiti Wall Art

Living in an urban area, we get to see all kinds of 'art' just by going on our daily walks.It's almost like going to an outdoor gallery as new things are popping up all the time.
When most people think of graffiti, they think of vandalism and gang tagging:

The gangs will write all kinds of cryptic messages to eachother staking out their claim to show they're in the area; it's kind of like how our dogs pee in certain spots. Some of our students, involved in this type of activity, actually tag at school, so I've even learned to decipher some of the 'code':

Given all this "conversation", it's actually illegal to buy or own spray paint within Chicago city limits. We also have the graffiti blasters who will promptly remove this kind of writing.
At the same time, we also have graffiti crews which are still illegal, but view graffiti as an art form. They go out and tag, and even get some really high up or unexpected places:

It's fun to have things pop up in unexpected, 'ugly' areas. Like this random octopus in the middle of an alley:

Or a random zombie. Miss M should look over her shoulder:

But beyond all the illegal activity, many people do recognize graffiti as an art form and they've created 'permission walls' where people can legally create street art to liven up the neighborhood.

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 And graffiti has also become a marketing strategy. Back when I worked in advertising, we had a whole graffiti campaign to advertise gum to a teen audience. It works because you don't realize it's advertising. Here is some kind of alcohol advertising:

Our area still has some old vintage ads on the sides of buildings, so you can tell it's not such a new idea:

And of course, some Blackhawk pride: