If there should be limits to public art, who should set and enforce them?

Yes, there are limits to public art. Such as graffiti.

Explanation:

The state or the city should be the ones to set and enforce the limits to public art.

because of the importance of consistency in data collection. but we have to evaluate the resource or information, and not just accept what is posted online since information available on the internet is not regulated for quality or accuracy.