On 6 February 2018, Elon Musk put his personal Tesla Roadster into space. For a very long time, this object will continue to orbit the sun before something perturbs its orbit. Some people consider this a memorial, and a worthy trophy to celebrate SpaceX's ascendance, but others malign the choice as polluting space, a sort of "Space Graffiti".
On 21 January 2018, another company put a reflective sphere in orbit whose only purpose is to be visible. Astronomers saw this as littering and disruptive to their activities, since it would ruin observations that the object passes through. Rocket Lab claims that the "Humanity Star" will bring people together, so it seems that this conversation is exactly the same as one about traditional graffiti.
Space is considered a public space for all humanity. We cannot casually dump garbage into the ocean or streets, why would we not expect space to have the same restrictions. Even if we agreed to these restrictions, how could we enforce them? SpaceX is a private American company and Rocket Labs is a private New Zealand-owned American company. These affairs are international, and will take time to set straight.
How can we treat space as a shared space without spreading needless graffiti or worsening Kessler Syndrome?
Pugwashites will discuss this Thursday over pizza!