Quote Originally Posted by vinjashira
you are underestimating vandalism. It is illegal as well and you can be prosecuted.

I aggree with Lady's human. If you mean well and you are really concern with the dog inside the car and you believe that it could be in danger then call the dog warden/rspca/police/other authorities. No need to take the law in your own hands.
True. But I just think that it would be a little OTT to create a huge hullabaloo over a window sticker. Unless this thing measures the size of a windscreen and has extra strong glue, then it's not really too much bother to peel it off.

Lots of people put flyers under the windscreen wipers of parked vehicles, perhaps it would be better to do that rather than make a sticker? I'm pretty sure that isn't illegal or businesses would be wary of doing it.