Imagine a city where graffiti wasn't illegal, a city where everybody could draw whatever they liked. Where every street was awash with a million colours and little phrases. Where standing at a bus stop was never boring. A city that felt like a party where everyone was invited, not just the estate agents and barons of big business.

You owe the companies nothing. You especially don't owe them any courtesy. They have re-arranged the world to put themselves in front of you. They never asked for your permission, don't even start asking for theirs.

The people who run our cities don't understand graffiti because they think nothing has the right to exist unless it makes a profit. The people who truly deface our neighborhoods are the companies that scrawl giant slogans across buildings and buses trying to make us feel inadequate unless we buy their stuff. Any advertisement in public space that gives you no choice whether to see it or not belongs to you, it's yours to take, rearrange and re-use.