Tagging: Good or Bad?

Tagging (and street art), you see it everywhere, even online with social media #hashtags.

Some of it is very clever, some is just vandalism. I enjoy great street art, especially in the small out-of-the-way places or the subversive.

But what makes it good or bad?

• Placement?
• Permission?
• Artistic Merit?
• Does it enhance or add value?
• Does it destroy?
• Does it claim ownership unjustly?
• Some may be just annoying.

What are your thoughts?