Personally, if any person did that to any car of mine, it would be they themselves who do the job of removing the stickers. 
Just to add to this write up:
To remove stickers from painted surfaces
If anyone ends up with stickers on the paintwork, first Donts:
1. Dont scrape! You will end up in removing the clearcoat at least!
2. As mentioned by Rohit, Dont use any solvents. Even diesel and the likes are best avoided(please dont ask chemistry based justifications!).
3. Dont use sharp objects. Fingernails are also harmful to modern paint.
4. Do not pull out the sticker with force.
Now for the procedure:
1. For Vinyl or plastic stickers - It is much easier to remove one. Keep a soap solution or a car shampoo. Use a wooden toothpick, dipped in the solution. Slowly pass it below the sticker and separate as much as you can. Now remove the tooth pick and dip it in the solution again. Pass it back into the separation and widen the gap. If this job is done slowly, it will help the soap solution spread out under the sticker and will lessen the adhesive strength. Just ensure you use lots of soap. After the sticker is removed, use a wax or polish to adda protective layer over the paint.
2. For paper stickers - There will be a thin plastic lamination to a paper sticker. This can be removed with a toothpick. Once this is done, the sticker would have lost its integrity. Soak and soak the sticker with soap solution every two minutes and the sticker will come off its own in some time. Again after drying the area, finish off with wax.
Usually, a frequently waxed car will be less reactive to stickers, and stickers can be easily removed from such cars compared to a car which has not been polished/waxed.
Where there is a wheel, there is a way!