If graffiti changed anything it would be illegal.

It's ok

It is illegal. It gives the population the idea they have the right to alter their environment, and that's dangerous.

Alter other people's property.

Agreed, that is a dangerous concept

*in ways that don't harm that person

	▲	browsingonly 11 hours ago \| parent \| next [-]
		Not all harm is physical.
	▲	bigstrat2003 13 hours ago \| parent \| prev [-]
		Nonsense. The owner almost certainly doesn't want someone's "art" to adorn his wall, and will then have to pay to restore the wall to its desired condition. That is material harm done to the building owner.