Any advert in a public space that gives you no choice whether you see it or not is yours. It’s yours to take, re-arrange and re-use. You can do whatever you like with it. Asking for permission is like asking to keep a rock someone just threw at your head.
You owe the companies nothing. Less than nothing, you especially don’t owe them any courtesy. They owe you. 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.
- Banksy