Hanging out dirty laundry

[Michaela G.]

So, I and a partner have created a creative community, with all residents being creative in some form. This is a private cul-de-sac and we made all outside space 'common area', for people in our community to hang out. 

Yesterday I found a line with laundry flapping in the wind, across the common area. I knew who's it was and texted the wife to please not hang out laundry in the area that is used by everyone (they don't have private yards anywhere. They're renting the inside of their house). 

The husband called me and we got into a heated argument, because he wants to save on electricity and I don't want him to do this in our public area. It's trashy.

I then brought them a letter, signed by me and my partner, telling them that it's not acceptable to hang laundry in the common area. It rained later and after the laundry was gone and I brought the line and put it in front of their door. 

This morning I found the line back up, full of clothes, that are spray painted 'this is art'. So, now I'm ticked off, because he's doing this to spite me, but in the meantime he's disrespecting everyone that's living there by doing this. 

I put up a 1-day notice , that he tore apart in front of me and told me that I'm f*cking with the wrong person. I yelled back that if he things that starting a war with his landlord is a smart thing to do then he'll better dream on. Also, that I would no longer communicate with him verbally and everything is now in writing and legal route. 

Now I'm trying to figure out how to file for eviction, because that situation is obviously not addressed in the lease. I would have never thought that anybody would be so disrespectful and hang out their laundry in the common area where people sit and eat etc. 

How can I, as a landlord, enforce a rule, that we had to set as a reaction to something we didn't expect?