It doesn't breach the peace? Oh, c'mon! The neighbors are offended and up in arms -- even the Associated Press is involved, making this a nation-wide story!
And yes, this is classic passive-aggressive behavior. He did it only after he was arrested as an in-your-face symbol of defiance. I'm betting a neighbor dropped a dime on him and he's all pi$$ed off about it.
So, for the second time, you're saying behavior that breaches the peace, is offensive to others, and is passive-aggressive is acceptable?
It's incredibly immature, and in the parlance of my beloved New England, it's "gay," but he's not breaking any laws here (though this here pothead would be pissed off if he were my neighbor). I hate those damn pink flamingo statues and the Mary-in-a-bathtub statues people put out, too.
They are offended. That's not a breach of the peace, nor is it a violation of their rights. How they react to that offense is their choice. "Up in arms"? Really? They're within their rights to bear them, certainly, but if they point them at their neighbor, it would constitute a threat.
And yes, this is classic passive-aggressive behavior.
Look up passive-aggressive.
Please don't tell me your argument is passive-aggressive behavior in itself should be illegal. It would make me think you are some sort of statist mock-up.